68 Cuda 383 vs a 360

[fishmens67]

I have already offered my opinion earlier in this thread. If the cubic inch spread was greater, say 40-50 rather than 23, then I would go for the BB every time. But 23 isn't much, & I think the individual traits of each engine need to be considered, along with & most important, the intended use. The OP wants a mild driver; that means limited rpm.
The shorter rod/stroke ratio of the 360 favours low end tq & will likely equal the 383 even though it is down 23 cubes. All in a lighter & easier to install package. The 383 Chevs seem to punch above their weight & they are a 350 with a 1/4" longer stroke. Similarly, the 408 Mopar. Another stroked engine. Both have shorter rod/stroke ratios.
My Motors Manual covers 1973-78 models. The performance 360/4 bbl had a 320 ft/lb tq rating. The highest I could find for the 383 [ actually 400 by then ] was 330 ft/lb in 1974. So the 360 was down 10 ft/lb against the 400, which has 17 more cubes that the 383 & the 400 has 40 cubes more than the 360. There is a good chance that had the 383 still been in production, the 360 might have beaten the 383 in tq, or certainly equalled it.

Let's not compare factory 360's with any Chrysler big block. Fact is the 360 was a turd from the factory.
Stock 383 2bl out performs 360 2bl every day and twice on Sunday.
But that isn't what we're talking about.
The OP should just go with the 360 or the small 360 stroker for what he's wanting to do.

 

[DionR]

Let's not compare factory 360's with any Chrysler big block. Fact is the 360 was a turd from the factory.

Then the '72 and '73 340 was a turd, too? 'Cuz the '74 360 4BBL that replaced it was rated better than that version of the 340.

Stock 383 2bl out performs 360 2bl every day and twice on Sunday.

Not sure I would disagree, except that not all 360's were 2bbl.

Unfortunately, an HP 360 was short lived and it wasn't long after '74 that the 4bbl on the 360 really only meant a different induction and better durability but not much performance. But at least there was an HP 360 that got all the 340 stuff from the factory.

Wonder what cam the '75-6 E-58 360 got. Something for a different thread.

 

[MOPARMAGA]

DionR, the 400 replaced the 383, as a factory built engine the 400 wasn't an upgrade. (Except for the future stroker engine combos)
Also the 72-73 340s weren't as good as the early 340s, so just because the 360 replaced it didn't make it an upgrade, remember chrysler was leaving performance in the early 70s.
The early 360 was a great engine but wouldn't keep up to say a 68 340

 

[fishmens67]

Then the '72 and '73 340 was a turd, too? 'Cuz the '74 360 4BBL that replaced it was rated better than that version of the 340.



Not sure I would disagree, except that not all 360's were 2bbl.

Unfortunately, an HP 360 was short lived and it wasn't long after '74 that the 4bbl on the 360 really only meant a different induction and better durability but not much performance. But at least there was an HP 360 that got all the 340 stuff from the factory.

Wonder what cam the '75-6 E-58 360 got. Something for a different thread.

If you drove anything with a big block or 340 from the 60's you would know every Chrysler engine after 71 was a turd. lol
I do like the newer 5.2 , 5.9 and Hemi platform .
If I was just starting out I would do the modern Hemi swap.

 

[DionR]

I've struggled with this question myself.

For some odd reason, there is soft spot in my heart for the 383 and I've always wanted a BB Duster. I was moving forward with a '73 Duster I was going to put a B motor in when my son wanted his first car back otherwise I would have had one of each to compare. Just something cool about the look of a BB in an A-Body.

At the same time, if the goal is a fun cruiser, then seems like simplicity is the better path and the 360 would win. This assumes that there are no horsepower or timeslip goals, because then it comes down to which is going to have the most potential. But if "fun" is the goal then both will deliver.

Just seems to me that if you aren't chasing ooh's and ah's when you pop the hood, the easiest path is a Magnum 5.9 with a cam. Bolt in with no aftermarket parts or fabrication, PS work, easy to source everything and makes enough HP to run 12's if you want. An LA 360 would be a close second, but only because it is more likely to be worn out while the 5.9 probably still shows crosshatching at 200K miles, I know mine does. But a low mile LA 360 would probably work great and might be easier since a Magnum compatible intake might be difficult to source, just have to find that low mileage 360 somewhere. And the LA/Magnum has the added advantage that there is still a set of headers (Doug's) that fit ok and don't cost $1000. The BB option only has TTI unless you can find a set of used Tri-Y's.

Would a 383 or similar low deck BB work the same? Probably. Just a little more work sourcing motor mounts or fabricating a K-frame and aftermarket radiator. But I would argue that unless you rebuild the 383, it is just as worn out as the LA 360, if not more. After you get it in there, certainly more stuff available for a low deck (except headers).

One thing that turned me off on the low deck was the lack of availability for an EFI intake. There is at least one for the 440, and 2 different versions for the small block, but nothing (so far) for a B motor.

No budget streetcar? Gen3 and EFI in a heartbeat.

But enough about my opinion.

 

[SLOPAR72]

If you drove anything with a big block or 340 from the 60's you would know every Chrysler engine after 71 was a turd. lol
I do like the newer 5.2 , 5.9 and Hemi platform .
If I was just starting out I would do the modern Hemi swap.

Hey now you callin' my 72 340 a turd lol..... Can't disagree with your statement. Driving a 71 340 car I bought that was in good running condition back in the day leave no doubt the good stuff ended in 71.

I wouldn't hesitate to do a 360 today with a set of TF's on top. Had those TF's been available when I built my 512 that RB setup would have never come to fruition.

JW

 

[MOPARMAGA]

I've struggled with this question myself.

For some odd reason, there is soft spot in my heart for the 383 and I've always wanted a BB Duster. I was moving forward with a '73 Duster I was going to put a B motor in when my son wanted his first car back otherwise I would have had one of each to compare. Just something cool about the look of a BB in an A-Body.

At the same time, if the goal is a fun cruiser, then seems like simplicity is the better path and the 360 would win. This assumes that there are no horsepower or timeslip goals, because then it comes down to which is going to have the most potential. But if "fun" is the goal then both will deliver.

Just seems to me that if you aren't chasing ooh's and ah's when you pop the hood, the easiest path is a Magnum 5.9 with a cam. Bolt in with no aftermarket parts or fabrication, PS work, easy to source everything and makes enough HP to run 12's if you want. An LA 360 would be a close second, but only because it is more likely to be worn out while the 5.9 probably still shows crosshatching at 200K miles, I know mine does. But a low mile LA 360 would probably work great and might be easier since a Magnum compatible intake might be difficult to source, just have to find that low mileage 360 somewhere. And the LA/Magnum has the added advantage that there is still a set of headers (Doug's) that fit ok and don't cost $1000. The BB option only has TTI unless you can find a set of used Tri-Y's.

Would a 383 or similar low deck BB work the same? Probably. Just a little more work sourcing motor mounts or fabricating a K-frame and aftermarket radiator. But I would argue that unless you rebuild the 383, it is just as worn out as the LA 360, if not more. After you get it in there, certainly more stuff available for a low deck (except headers).

One thing that turned me off on the low deck was the lack of availability for an EFI intake. There is at least one for the 440, and 2 different versions for the small block, but nothing (so far) for a B motor.

No budget streetcar? Gen3 and EFI in a heartbeat.

But enough about my opinion.

Honestly a 5.9 magnum moves a 4600 pound Dakota r/t & ram 1500s just fine in a 3200 a-body it would move fine better

 

[DionR]

Also the 72-73 340s weren't as good as the early 340s, so just because the 360 replaced it didn't make it an upgrade, remember chrysler was leaving performance in the early 70s.

I agree the later 340's weren't as good as the early ones. But some see all 340's in the same light and the '74 360 4BBL was an upgrade from the later ones based on rated HP and torque.

The early 360 was a great engine but wouldn't keep up to say a 68 340

No argument if we are talking factory stock. Give the 360 the same compression, cam and heads and it becomes more difficult to say. But this thread isn't about "is the 360 better than the 340", I was only using it as an example to say the moniker of "turd" maybe shouldn't be broad brushed like it was.

Besides, even if the OP has a good running LA 360, I doubt it would go in the car stock. A cam and intake alone would invalidate any argument as to how it would run if it was based on factory offerings. Same for the BB.

 

[MOPARMAGA]

I agree the later 340's weren't as good as the early ones. But some see all 340's in the same light and the '74 360 4BBL was an upgrade from the later ones based on rated HP and torque.



No argument if we are talking factory stock. Give the 360 the same compression, cam and heads and it becomes more difficult to say. But this thread isn't about "is the 360 better than the 340", I was only using it as an example to say the moniker of "turd" maybe shouldn't be broad brushed like it was.

Besides, even if the OP has a good running LA 360, I doubt it would go in the car stock. A cam and intake alone would invalidate any argument as to how it would run if it was based on factory offerings. Same for the BB.

Yes, any of them with a few upgrades is fine. Some respond better than others but you're right.

 

[DionR]

If you drove anything with a big block or 340 from the 60's you would know every Chrysler engine after 71 was a turd. lol

LOL. Gotcha.

I do like the newer 5.2 , 5.9 and Hemi platform .
If I was just starting out I would do the modern Hemi swap.

I had to dial myself back on the G3 swap. I was all in and looking for a motor when I realized that the current 360 I have should be more than enough. It might never get the mileage or make the same HP (all out), but do I really need all that? In the end, I guess I am getting older and a cam swap and Magnum EFI on my current motor is probably enough (at least for now).

 

[rumblefish360]

Then the '72 and '73 340 was a turd, too? 'Cuz the '74 360 4BBL that replaced it was rated better than that version of the 340.



Not sure I would disagree, except that not all 360's were 2bbl.

Unfortunately, an HP 360 was short lived and it wasn't long after '74 that the 4bbl on the 360 really only meant a different induction and better durability but not much performance. But at least there was an HP 360 that got all the 340 stuff from the factory.

Wonder what cam the '75-6 E-58 360 got. Something for a different thread.

Here is my ***** about this honest & factual statement.
How many of these engines are running around today with there exact stock equipment AND are ready to be swapped in place a turd engine.

Answer = ZERO!

The the statement is an old stall one that no longer be argued or applied.

So where we really are is a place of what you want to build. Unless there is a Daddy Warbucks giving away vintage sealed replacement engines?

If you drove anything with a big block or 340 from the 60's you would know every Chrysler engine after 71 was a turd. lol
I do like the newer 5.2 , 5.9 and Hemi platform .
If I was just starting out I would do the modern Hemi swap.

Im not sure how much work is involved and how long it would take to do, but a modern HEMI swap would be a great power plant. How much for the materials? IDK myself.

 

[rumblefish360]

From the 440source page on stroking the 383, 2K gets the kit. Cheaper than a small block.

383 >> 496. (4.250" stroke/6.535" rod) Approximate Bobweight: 2150

Turn that docile factory 383 block into a fire breathing, pavement twisting engine of almost 500 cubic inches, and no one (even the car show judges) will ever be able to tell it's not a 383... until they go for a ride! The time has arrived to dust off those 383 blocks we've been leaving in the back of the garage all those years. Chrysler made 4 times as many 383's as they did 440's, and it's no longer necessary to dig up a 440 block to get almost 500 cubes! The low deck, 4.250" stroke version of our Platinum Series crank used in this kit has the smaller 2.200" (big block Chevy sized) journals, and the counterweights are finished at the smaller "B" engine size, to ensure they will drop right into the block with no counterweight clearancing issues. Depending on the block used, many of customers find this kit drops right in with no modifications whatsoever! We now offer fully chamfered "B" engine main bearings as an available upgrade! We keep all the kits listed below normally on our our shelf and ready to ship, usually within 24 hours!

Additional Kit options:
Upgrade to ARP2000 rod bolts: $99 This upgrades the standard ARP8740 bolts(which ARP rates up to 850 horsepower,) to ARP 2000 bolts, which they rate up to 1200 horsepower.
Upgrade to Chamfered "B" engine main bearings: $99
Upgrade to Ultralight Crankshaft: $150 (Details HERE)


383 >> 496. (4.250" stroke/6.535" rod) Stroker Kits Available:

Bore Size: Dish (-) or Dome (+) CC's Compression Height: Distance Below Deck: 65CC 72CC 75CC 78CC 80CC 84CC 86CC 88CC Kit Part#:
4.280"
(.030 over) -4
(Flat-top) 1.320" -.000" 13.7 12.7 12.3 11.9 11.6 11.3 11.1 10.9 383.496.5040
4.310"
(.060 over) -4
(Flat-top) 1.320" -.000" 13.9 12.9 12.5 12.1 11.8 11.4 11.2 11.0 383.496.5050
4.280"
(.030 over) -12
(Dish) 1.318" -.002" 12.4 11.6 11.3 11.0 10.8 10.4 10.2 10.1 383.496.5043
4.310"
(.060 over) -12
(Dish) 1.318" -.002" 12.6 11.7 11.4 11.1 10.9 10.5 10.4 10.2 383.496.5053
4.280"
(.030 over) -20
(Dish) 1.320" -.000" 11.6 10.9 10.6 10.3 10.1 9.8 9.7 9.5 383.496.5042
4.310"
(.060 over) -20
(Dish) 1.320" -.000" 11.7 11.0 10.7 10.4 10.2 9.9 9.8 9.6 383.496.5052

 

[DionR]

Here is my ***** about this honest & factual statement.
How many of these engines are running around today with there exact stock equipment AND are ready to be swapped in place a turd engine.

Answer = ZERO!

The the statement is an old stall one that no longer be argued or applied.

So where we really are is a place of what you want to build. Unless there is a Daddy Warbucks giving away vintage sealed replacement engines?

Absolutely agree.

Im not sure how much work is involved and how long it would take to do, but a modern HEMI swap would be a great power plant. How much for the materials? IDK myself.

I got it down to $4750. That was buying a $700 engine, headers, etc. and $750 for a cam and refresh on the motor. Motor must have come with a harness and PCM as that wasn't in the list. It also didn't include a fuel system, I must have planned to use the tank I built already so I didn't include it. But it did include costs for a car TC cover and intake and WP/Alt.

 

[rumblefish360]

I got it down to $4750. That was buying a $700 engine, headers, etc. and $750 for a cam and refresh on the motor. Motor must have come with a harness and PCM as that wasn't in the list. It also didn't include a fuel system, I must have planned to use the tank I built already so I didn't include it. But it did include costs for a car TC cover and intake and WP/Alt.

Thanks Dion. So, you grabbed an engine with computer and harness for $750?
And now your left with the fuel system to contend with, correct? If so, that’s not to bad at all.
Thanks again.

 

[DionR]

Thanks Dion. So, you grabbed an engine with computer and harness for $750?
And now your left with the fuel system to contend with, correct? If so, that’s not to bad at all.
Thanks again.

I didn't follow through with it. I was tracking a 2014 from a truck on FB Marketplace and running numbers. I was going to offer him $700 and then swap a 6.4 cam into it and delete the MDS stuff which put me at about $2000 for the motor/harness/pcm with a car intake and FEAD. The rest was oil pan, mounts, headers, etc. I would guess that another $500 would solve the fuel system and put you on the road, or close to it.

 

[Ottmundr]

Dumb Q: if you're going to do a stroker kit on a 383, is there ANY downside to doing the 496 vs the 438? on a mainly street car.

Compression height and fully supported rings?
Rod ratio?
Piston speed?

I'll try to remember to break out my books and calculator when I get home tonight. I have a phone interview for a new job this evening so I may not be able to post until late.

 

[mygasser]

I have already offered my opinion earlier in this thread. If the cubic inch spread was greater, say 40-50 rather than 23, then I would go for the BB every time. But 23 isn't much, & I think the individual traits of each engine need to be considered, along with & most important, the intended use. The OP wants a mild driver; that means limited rpm.
The shorter rod/stroke ratio of the 360 favours low end tq & will likely equal the 383 even though it is down 23 cubes. All in a lighter & easier to install package. The 383 Chevs seem to punch above their weight & they are a 350 with a 1/4" longer stroke. Similarly, the 408 Mopar. Another stroked engine. Both have shorter rod/stroke ratios.
My Motors Manual covers 1973-78 models. The performance 360/4 bbl had a 320 ft/lb tq rating. The highest I could find for the 383 [ actually 400 by then ] was 330 ft/lb in 1974. So the 360 was down 10 ft/lb against the 400, which has 17 more cubes that the 383 & the 400 has 40 cubes more than the 360. There is a good chance that had the 383 still been in production, the 360 might have beaten the 383 in tq, or certainly equalled it.

this all sounds good theory but think about another comparison, at only 22 cu in difference does anyone ever recommend a 318 over a 340? hell no!
so it's the 383 for me, there's just more potential for upgrades in the future. and we always eventually want 'more', lol.
neil.

 

[DionR]

this all sounds good theory but think about another comparison, at only 22 cu in difference does anyone ever recommend a 318 over a 340? hell no!

Not really a valid argument since a 340 and 318 fit the same. A 383 and 360 take different parts to bolt in.

so it's the 383 for me, there's just more potential for upgrades in the future. and we always eventually want 'more', lol.
neil.

Can't argue that the bigger bore and better heads make for some good potential. Just a matter of whether or not someone is going to ever need that potential.

 

[rumblefish360]

That’s true. No sense building a 500 cube tunnel ram 6.00 in the 1/4 beast if your just going to the car meet. Or mostly no sense….

 

[Ottmundr]

Get this book. $30 on amazon. After reading it, I decided to build a 3.580" stroke 360 rather than a 4" stroke 360 to 408. The cost of a new cast Scat internal balance crank was the same. Pistons, rings, bearings, et cetera would have been the same. I want this engine to last even if I beat the living snot outta it.
I do have a 400 block that I plan to build a few years down the road. Plans for that is a 470 for the compression height and rod length over the 451, the difference in piston speed is negligible. It's been sitting in my shed for about 5 years now. I'm in no rush.

If you want the displacement, go with a 383 or a 400. You get;

• Lower piston speed and stress on parts
• The low deck, how many pounds more mass over the front axle than the small block?
• Plenty of options for aluminum heads from 440 Source to Trick Flow, and everyone else.
• Aluminum intakes...
• The option of a whole fiberglass front clip bumpers and rear decklid, as I plan from AAR Fiberglass, which will lighten the heck out of it.
• You can lose the interior, et cetera. Over on bigblockdart.com there used to be a page that broke down all the stuff you could do to lose weight by swapping out parts. Here's an archive.

Put your big block dart on a diet

Copy and pasted below as well.

https://www.amazon.com/dp/1934709476/?tag=fabo03-20

Put your big block dart on a diet

Information compiled by various members of this site. Feel free to send along any info we could add to this list

Vehicle Part factory weight fiberglass weight lighter part lighter part weight weight savings
63-66

67-69 ft bumper w/bkts 29 lbs 6 llbs 23 lbs

70-72 hood 56 lbs 16 lbs 40lbs
ft bumper w/bkts--dart 30 lbs 6 lbs 24 lbs
ft valance pan 6 lbs 3 lbs 3 lbs
ft fender w/extension 24 lbs 7 lbs 17 lbs
doors-complete 70 lbs/ea 28 lbs/ea 42 lbs
dash complete 32 lbs 8 lbs 24 lbs
trunk lid--dart 45 lbs 10 lbs 35 lbs
r bumper w/ bkts--dart 36 lbs 8 lbs 28 lbs
r bumper w/bkts-duster 40 lbs 6 lbs 34 lbs
rear sideglass 12 lbs/ea lexan copies 1 lbs/ea 11 lbs
rear window regulators 11 lbs/ea
73-76 ft bumper---'73 58 lbs 6 lbs 52 lbs
dash complete 32 lbs 8 lbs 24 lbs
r-bumper w/bkts 73 duster 40 lbs 6 lbs 34 lbs

engine parts
400 engine block--empty 222 lbs
complete b-motor sht. blk 350 lbs
452 head 51 lbs/ea stage 6 head 26 lbs/ea 25 lbs/ea
iron intake 40lbs aluminum intake 15lbs 25 lbs
iron ex. manifolds 50 lbs headers 25 lbs 25 lbs
iron water pump/housing 20 lbs aluminum, setup 5 lbs 15 lbs

driveline/chassis
833 4-speed m/t trans 115 lbs bb727 a/t trans 120 lbs
flywheel-steel-typical 35 lbs
clutch and steel bell hsg 65 lbs t-converter-typical 20 lbs a/t lighter@ 75lbs total
power steer gear box 34 lbs manual steer box 9 lbs
p/s pump and hoses 12 lbs 37 lbs total lighter
stock upper contrl arms 4 lbs RMS tubular arms 2 lbs 2 lbs
stock disk setup 50 lbs/side
stock brake booster 10 lbs
complete w/wiper setup 6 lbs
master cylinder 6 lbs alum m/c w/ adapter 3 lbs 3 lbs

 

[RustyRatRod]

I keep seeing "piston speed" pop up. First off, it's completely arguable that a short rod motor (higher piston speed) is more desirable on the street. Quicker to rev, quicker to get the reciprocating mass up to speed and "all that jazz".

Having said that, IMO, you'd be hard pressed to notice the difference in feel between a long rod motor (slower piston speed) and the short rod motor (faster piston speed).

I just don't think it's all that important. And don't come at me about higher rod ratios unloading the cylinder walls and wearing piston skirts less, blah blah blah. Just look at the Chevy 350. Has what most consider a "crappy" 1.6 rod ratio, yet those little motors run good and are very durable. If rod ratios were so all fired important, everybody would be building the 1.88 ratio 383s and 400s, but that's not the case. Everybody strokes them making the rod ratio "worse" as far as the theory goes.

It just doesn't make that much difference.

 

[mygasser]

That’s true. No sense building a 500 cube tunnel ram 6.00 in the 1/4 beast if your just going to the car meet. Or mostly no sense….

there's a lot that do and common sense doesn't seem to be part of a lot of builds these days, lol. it's what we 'want' (often to brag about at said car meet), not what we 'need'. oh, and lastly you gotta love a tunnel ram
neil.

 

[rumblefish360]

@mygasser Funny but true! I have 2 400B blocks. One I still want to use as a 400. Plenty of cubes for the street.

 

[Jeremiah (jd)]

Compression height and fully supported rings?
Rod ratio?
Piston speed?

I'll try to remember to break out my books and calculator when I get home tonight. I have a phone interview for a new job this evening so I may not be able to post until late.

Let's be realistic:

There are plenty of factory engines running around with short compression heights that expose the oil ring to the pin boss. No big deal they use oil support rails. A 4.250" stroke crank typically uses a 1.320 compression height. A stock 200k mile ls 6.0 uses 1.342 with a much thinner metric ring pack. Short pistons are a non issue here.

Most of these street engines never see the high side of 5500-6000rpm. If they do it isnt for long and typically the engine was not loaded like a drag car. Or worse, wrung out like a SCCA road race car. My point is that engines going into hobby cars owned by middle age to retirement age drivers do not see the abuse people make them out to endure. Bottom line is most guys building stroker engines finally get them in the car and then drive around "with you wallet under the gas pedal" because you dont want to break your "yep she's a stroker all right " 10k engine before the Friday night McDonalds fonzie style cruise in. All you have to do to be on top is have cutouts and use words like roller and stroker to makemthose crying doll easter egg looking street rod guys retreat for another McRib or whatever.

In my research piston speed does not become a durability issue until you start seeing some RPM. I have a 400 based 511 going together than will see north of 8500rpm. I am more concerned about oil contro and valve train geometry than piston speed.

Rod ratio...it is what it is. Built with your goals in mind and don't sweat the egghead math too much. Leave that to the OEM`s that have to support a 100k warranty.

 

[CRUZE 418]

Just changing spark plugs alone puts my vote into the small block pile.