360 vs 383

383 or 360 ?

  • overall, 383 all things considered

    Votes: 31 58.5%

  • overall, 360 all things considered

    Votes: 22 41.5%
  • Total voters
    53
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Wonder what the max HP that can be pushed through a stock block 383 and 360 ? 383 is noted for having the webbing and the stronger block vs any SBM.
 
318willrun said:
Wonder what the max HP that can be pushed through a stock block 383 and 360 ? 383 is noted for having the webbing and the stronger block vs any SBM.
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I'm pretty sure Jim Laroy pushed a 400 block to 787 hp with 451 cubes.
 
DionR said:
This page says the '71 340 (Note - not detuned) net rating was 235/310.

https://www.hamtramck-historical.co...lershipDataBook/1971/71_Valiant_Duster_14.jpg

'74 360 factory rating (still net) was 245/320.

'73 340 was 240/295.

Still factory ratings so they could have monkeyed with them, NHRA sure didn't seem to think they were accurate.
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It's kind of interesting (to me) to compare the rated rpm's for these motors.

__________HP________TQ
'71 340 - 235@5000 - 310@3200
'73 340 - 240@4800 - 295@3600
'74 260 - 245@4800 - 320@3600

Doesn't make sense to me why the '73 340 with lower compression and a log manifold on the right was rated 5 hp higher than the '71 340. But the rated RPM is different, too. Maybe the first generation TQ hurt the hp on the '71? I mean, all three have the same cam so it would seem like peaks would be pretty close, right?
 
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abodyjoe said:
not sure chrysler has/had it in them to build anything that would compete with an LS..
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There is a European team that campaigned a V8 Viper by disabling 2 cylinders in the V10 block, and they did pretty good. The Vipers were dominate so the other manufacturers got the rules adjusted to slow them down and the team found loopholes to keep competing, and winning, with the Vipers.

Just seems like an avenue that was never really explored and I wonder what could have happened. Maybe they couldn't have competed with the LS, but it was an inline valve all aluminum monster that might have given it a run for the money.
 
For me, I think the decision between a 360 or 383 is too project dependent to say which way I would go in a theoretical thread like this.

I think the 383 has some real advantages over a 360. I think the available aftermarket BB heads are better and I like the shorter stroke and bigger bore, distributor location, external oil pump and dry intake. But the only reason I can think of to build one is if I really wanted a BB. And I would probably lean towards a 383 over any of the other BB's because I am sure it would be big enough for what I would want and wouldn't be cylinder head limited as much. Built right, it would rev like a big 340.

But most of the time I would probably just do the 360. I can find a 5.9 that probably still has cross hatching (good luck with a 383), run a roller cam relatively cheap, have the option for port EFI if I want to get "wild" and make all the power I need.

I like the smaller engines, in theory they can do enough and use less gas at the same time and I've never lusted after a 500 cid motor. Not that the idea doesn't sound cool, but I don't need it and I'd like to be able to road trip my car and not stop at every gas station along the way. Helps that I'm not competing or anything. Just has to be something I like and want to drive, so the only competition is internal.
 
318willrun said:
But on the line of mechanics and ease of work'n on them, if we just look on top.......
the 383 intake swap is a marvel compared to the small block, as the 383 has no coolant through the intake, less bolts, and the gasket can be re-used right in place. Also, distributor swapping/tuning on the 383 is obviously easier up front than the rear. Water pump also, just 4 bolts and a small pump. Also, we could head down the block to the oil pump and oil pan ....
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The distributor up front just means it’s in the way. Plus, it’s quicker and easier to pull the distributor and change the curve so the up front distributor is just a PITA.

I can change an intake almost as fast on a small block as I can on the BB. The extra time is dropping some coolant.

So those two things are non starters.
 
273 said:
I'm Guessing most people wouldn't run a ritter block cause of it's weight then? I'm sure strangely people would have little problem running a 4.25" bore taller deck small block for better rod ratios for 4-4.25" crank with add weight for strength.
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The extra weight is more than made up for in ring seal and other modifications to control oil.

Also, a little extra weight up front may make it easier to find more hook. You’ll have to think that one through. It will make sense when you get it.
 
Newbomb Turk said:
I can change an intake almost as fast on a small block as I can on the BB.
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I call bullshit.
Newbomb Turk said:
t’s quicker and easier to pull the distributor and change the curve so the up front distributor is just a PITA.
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If you say so, how tall is the step ladder you use on pickup truck. lol 4, 6 foot? lol
It's nice changing the oil filter on a big block without having to lay on your back, it's as easy as just reaching over. :D
 
Newbomb Turk said:
The distributor up front just means it’s in the way. Plus, it’s quicker and easier to pull the distributor and change the curve so the up front distributor is just a PITA.

I can change an intake almost as fast on a small block as I can on the BB. The extra time is dropping some coolant.

So those two things are non starters.
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I know you know this, but the small block's have 4 more bolts, coolant, top radiator hose, bypass hose, and I've never had a problem re-using the intake gaskets on the BB's. I like both engines, but this is just a fact.

Yes, I agree, the distributor is in the way on a BB vs SB, but when distributor work is needed, the BB has the better position in my opinion. But if no service is needed, i like it in the back like a SB
 
fishmens67 said:
I call bullshit.

If you say so, how tall is the step ladder you use on pickup truck. lol 4, 6 foot? lol
It's nice changing the oil filter on a big block without having to lay on your back, it's as easy as just reaching over. :D
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Call bullshit all you want but I can swap out an intake that fast. It’s not any quicker with a pig iron big block.

I mean if six extra bolts slows someone down that much they need to look to do other work. Like working a drive through.
 
318willrun said:
I know you know this, but the small block's have 4 more bolts, coolant, top radiator hose, bypass hose, and I've never had a problem re-using the intake gaskets on the BB's. I like both engines, but this is just a fact.

Yes, I agree, the distributor is in the way on a BB vs SB, but when distributor work is needed, the BB has the better position in my opinion. But if no service is needed, i like it in the back like a SB
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lol, come on. I said 6 extra bolts but it’s 4.

How long does it take to undo two hose clamps?

As far as the distributor being up front, you still have to deal with the fact that to run a rear sump pan the suction side of the pump is a mile away from the sump.

I get it that many think there is some trick **** with the BB but when you apply logic and experience it becomes evident it’s not what it’s cracked up to be.
 
I guess some folks are totally ignoring the stock eliminator I spoke of earlier. Those were the 343 HP 383. They mopped it up in stock eliminator.
 
Cuprum-74 said:
Yup!
I always tell my adult sons this: Stock means diddly squat, it's what you build not buy.
Awhile back I saw a yellow 1975 Pontiac Trans Am for sale with a 455 "HO". in the late 90's, my brother almost bought it, I like Pontiacs but stuck to Mopars.
Factory rated at a whopping 200 HP and 330 ft lbs of torque stock.
1/4 mile in 16.12 seconds... Talk about a turd.
*Edit* Also those Trans am's were a portly 3700+ lbs.
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that motor was a dog
To be fair that was t/400 with 2.56 gears
From a 90 mph roll on the hi-way it would have dusted most everything in 75
My buddys 76 ta 400 4spd with nothing but headers ran 14.5@98 with 3.23s i think it had pretty nice handling car not bad for a 400 smog motor in a boat
 
383 is so much more durable with the skirted mains and larger bore centers. I'm bias, but both really have their strong points.
 
I go 360 in an A body I don't care much for straight line speed, unless you are talking Alu 383
 
rmchrgr said:
I did and you're 100% wrong. Those are the "advertised" HP#s, not NHRA factored hp/weight. While I was at it, I looked up my old '68 Coronet 440/383 4bbl car specifically and the HP was 290 with OE heads and 295 with aftermarket ones. The minimum weight for that car is 3,416 lbs which is being generous.

If you want to prove these ideas to yourself, go to Wallace Calculators which are digital versions of the Moroso slide rule calculators that all the cool racers used way back when. So find the 1/4 mile stats calculator and input the 3,416 lb. minimum weight and then 290 hp and it spits out an ET of 13.49 @ 100.2 mph. Sounds pretty good for a decent running 383 with headers and slicks. Probably puts you down in U/stock with the 6 cylinder cars though.

From there however, you can input different numbers to see what class you might be able to run in competitively. Say you want to run in SS/IA with the '71 'Cuda I mentioned in one of my prior posts. To cover the SS/IA index of 10.70 in a '68 Coronet at that 3,416 lb. weight, it would take 750hp to go 9.66. Sounds fun! Who's paying?

I think we'd all like to know how to get at least 750hp out of a stock stroke 383 with OE or equivalent stock port/runner/valve sized aluminum heads (a difference of 5 hp) and a 625cfm Carter AFB. I'm all ears. No biggie for you though right 66fs, you got all the good parts laying around already because 383s rule and 360s drool. A few nights after work in the garage and a couple Sunday's worth of T'N'Ts and you're there, right?

I will couch that by saying that scenario obviously holds true for all engines in class racing including the more competitive ones. It's also why the shops that build class engines are some of the best out there. They understand the task and can make it happen within the restrictive parameters a particular combo might be saddled with. Yes, it's tough to do and takes a lot of time and money to sort those things out. Some guys are at it for years and are still off the mark because it's so difficult. To be sure though, none of that know how is based on fuzzy memories from 50 years ago either. But I digress.

Sorry to get too far off topic but whether "I was there back in the day" or not is irrelevant - facts are facts regardless of whether we understood them 50 years ago or now.


Ha, beat me to it.
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Yes, they are and different ways of calculating the number also. Those are not what class racers are running for hp, it is a factor to pair up racers. the real hp is much higher. Not a theoretical guy. No youtube, no calculators, no racing (my friends do that). Just built engines in the old days. Used to buy cars with 360's pull the heads, 727 trans, and 8 3/4 pig and send them to the scrap yard. A lot of back in the day has not changed. There are those who can, and those who can't. Who needs 750 on the street. If you seriously want that I can give you a contact for a "440" that will do more than that on pump gas. I am happy with around 300 real hp. Have fun playing with your calculator.
 
66fs said:
Yes, they are and different ways of calculating the number also. Those are not what class racers are running for hp, it is a factor to pair up racers. the real hp is much higher. Not a theoretical guy. No youtube, no calculators, no racing (my friends do that). Just built engines in the old days. Used to buy cars with 360's pull the heads, 727 trans, and 8 3/4 pig and send them to the scrap yard. A lot of back in the day has not changed. There are those who can, and those who can't. Who needs 750 on the street. If you seriously want that I can give you a contact for a "440" that will do more than that on pump gas. I am happy with around 300 real hp. Have fun playing with your calculator.
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I have to ask.... say you scrapped 360's then and do it now ... but your happy with 300 hp.... ??
 
This might have been mentioned somewhere in ten pages, but the 360 has one huge advantage..... an overdrive auto trans bolts right up. N/A for a big block.
But I voted for the 383 anyway.
 
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