1967 Barracuda 383 tuning tips

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Odmark91

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Hello. I have a 1967 Baarracuda with a swapped in 383 from a 1964 Chrysler. Its now stock apart from a holley 700 carb and headers.
Im looking to get a set of good aluminium heads, another camshaft (roller?) and maybe a slightly bigger carb, like a quickfuel 850 wich i have had good experience with in the past.
And also roller rockers, ignition etc.

I have never worked on Mopars before at all, maybe someone could point me in the direction of some good street/strip performance parts?

Ive looked a bit at the Edelbrock Performance Package, just becausr you get a lot in one kit and its pretty cheap, but i heard people before saying that its not worth it?

Anyway, i would really appreciate the help.
 
That's a pretty tame motor. Aluminum heads will help along with a little more cam. You didn't say what converter you have.
 
Probably just a stock converter, im not the one who did the engine swap so i really dont know. But ill add that to the purchase list.
 
If yur thinking like that, a low-deck 383 with a 440 crank, I think makes about a 425 cuber before boring.
but
A well built 383 is a screaming banshee. She is to BBs what the 340 was to the SBMs. At a factory stroke of 3.375 (compared to 3.315 for the 340) she can be a formidable hi-rpm weapon, without the monster torque associated with longer strokes. Torque which, in most A-bodies, just overwhelms the chassis.
The hick-up I anticipate is gearing such an engine for street. It won't take much to push that 383 to 400/450 horsepower, but it comes with the price of being at hi-rpm.
Nothing wrong with that except with 3.23s say, 5800 rpm with 28" tires is 58 mph.
To put the 383 power down where you mostly drive, say 35 mph is gonna be darn near impossible. And if you do gear it with say 3.91s, well then say goodbye to hiway cruising cuz 3.91s and 28s makes 65=3050 @ zeroslip, and that is not much fun, and usually uses a lot of gas to go anywhere. ..
So, IMO, if you do build to take advantage of the short stroke, you will want to consider a nuther gear for the transmission, an overdrive gear.
The A518 has a .69 od allowing you to turn ~2300 at 65 with 4.30s @ zero-slip. and the A518 has a low gear of 2.45, so 30mph@WOT will be about 4000 in first gear. In second 30 is about 2250@zero-slip. So that's kindof cool. You can be comfortably cruising along at 2250, and when you nail it, ZING! on the KD you are doing 4000, close to peak torque. First gear with 4.30s will rev the clock to 6000=45mph. On the shift, the Rs will drop to 3540, so whatever cam you choose, it better have the juice to pull you up outta that hole.
So now we have THREE data points to satisfy.
1) A first gear outshift at 6000, coming in at
2) 3540 in second at 45mph, and
3) A cruise rpm of 65=2300
Tuff call.
I suggest a solid lifter FLAT tappet cam , because;
A) that short stroke is gonna rapidly give up cylinder pressure with the kindof Intake closing angle that anything else will bring, and
B) you need an early closing intake angle to cruise at 2300 and get reasonable fuel economy, and oil-life
C) more importantly, you need a late opening exhaust to efficiently cruise at that 2300 number., and
D) the only way to satisfy all those requirements is with a solid FT cam.
So My choice is to have an after-lash Ica of say 64*, but I want an after-lash power duration of 110*. I do not care about overlap, Ok so
to be able to shift at 6000, she needs a cam to powerpeak at about 5300, so that would be an after-lash intake duration of 230/235 @.050
Allowing after-lash clearance ramps of 35*, that makes 265/270 intake duration.Lets use 268*after lash/232@.050, because this makes an off the shelf grind possible; the 268/276. Lets put it on a 110LSA,install it at 108, and the numbers come in at
268intake/118comp/110 power/276 exhaust/52 overlap; all are after lash numbers.
So now we are gonna need those aluminum heads and pump the pressure up to 11/1, and I get

Static compression ratio of 11:1.
Ica of 62*,
at 600 ft elevation
Effective stroke is 2.66 inches.
Your dynamic compression ratio is 8.88:1 .
Your dynamic cranking pressure is 184.06 PSI.
V/P (Volume to Pressure Index) is 167

BadaBoom! you got a tiger by the tail!, With flat-tops, a Tight-Q, and closed chamber alloy heads; suitable to be a Daily Driver, burning the cheapest gas money can buy.

>Can you make more power? Well sure; there is room in the build, but you will loose driveability.
>Can you get better fuel-economy? well sure; but it's gonna cost you performance.
>Do you need the overdrive? Only if you gotta hit the hiway at 65 mph. 4.30s are NOT hiway friendly; but they sure are fun in the city.
> do you need 4.30s? No, you can run less but then you will need more stall; about 200rpm per 10% smaller gear. and then your power peak moves up 10% per 10% gear change, so you might as well get a smaller cam; ~1 size per gearchange, but hang on, then your pressure is rising, and you gotta reduce the compression ratio, to keep the engine out of detonation.
> Everything is related to everything else; so once you set a course, IMO, you are more or less married to it.
> IF YOU STROKE it, NONE of this applys.
Happy HotRodding
 
what would a the compression ratio be on a stock 64 383?
a compression check might be a good starting point and go from there.
 
Thank you AJ for a very interesting read!! Sure is a lot to take in.

I just read an old Hot Rod article of them going from the stock 330 hp 383 B engine to 454.9 hp at 6,000 rpm, and 456.6 lb-ft of torque at 4,800 rpm with just a carb, intake, headers and cam swap. That means running that power on stock heads. Could this really be true?
 
take the magazine results and cut them in half.
if they report an increase of a 100.... think 50; ish
 
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I just read an old Hot Rod article of them going from the stock 330 hp 383 B engine to 454.9 hp at 6,000 rpm, and 456.6 lb-ft of torque at 4,800 rpm with just a carb, intake, headers and cam swap. That means running that power on stock heads. Could this really be true?

For a Streeter, the problems with a power peak at 6000 are twofold;
1) what gears are you gonna HAVE to run?
2) what Stall you are gonna HAVE to run?

6000 with typical 3.23 gears and 28s is 60mph, so you have a one gear to 60 combo. With 3.55s yur gonna hit ~6600, and that usually calls for a shift. Anything after 3.55s WILL require a shift, and that's when the nose drops and yur done.
So right away you sorta limit yourself to 3.23s or 3.55s.

But worse is that the cam to powerpeak at 6000 is probably a fgriggen huge unstreetable beast.
But worse than that is, The powerband of most cams is rarely wider than 1500 to 1800 rpm. So when you peak at 6000, you might carry that to 6400 and on the shift, the Rs drop to 59%, so ~3800, for a drop of 2600, well outside the powerband of that cam.
But even worse is what happens to the bottom end, off-the line jump. It just goes away; Crimminy a 5.2Magnum will blow it away; both with same stall TCs.
But even worse is what happens to the cylinder pressure. With iron heads you run into a wall at about 165psi and pumpgas. and with a cam as big as is required for a 6000 rpm power peak, finding 165psi is gonna be tuff, and if you can't make it, yur bottom-end goes away, or you need a higher stall TC to get off the line.
So yes; maybe you can make 454.9hp, but it comes at an rpm that you don't normally drive, and at a huge cost to street performance.
Where do you spend most of your time? would it be idle to 40 mph? I'm guessing yes. So, what gears do you want to run? Most of us streeters top out with 3.55s so we can hit the hiway at 65=2770(zeroslip) with 28s.. That means 40 mph in first gear is ~4400 at WOT. Well then,you want the bulk of your power from stall to 4400. Make sense? What good is 455 hp at 6000/55mph if you only go there for say 1 minute a week, compared to say 15 hours a week at below 40 mph; or whatever; you get the idea.
There is no Mopar streetable combination of 727 transmission and rear gears that will get you 6000@40 mph. It does not exist. The closest you can get is 4.88s, which is not streetable at all.And you still have not addressed the complete lack of traction with 4.88s.

On the street, if you can't make it hook, more than 350/380ish hp is kindof a waste. I mean, you might ET a hair quicker in the zero to 60mph contest, but firstly, it won't be by much, and secondly, IMO, the sacrifices made to stay with the short stroke, are just not worth it. and thirdly; what your engine lacks in power, you can usually make up for with gearing.
The combo I earlier outlined, is based loosely on my 367 which is a terror at 93mph in the Eighth. But it already is on the limit for an HFTcam (IMO) cuz I just cannot get good fuel economy out of the early-opening exhaust valve. My next cam, if there ever is one, is for sure gonna be a fast ramp solid-lifter design, and I'm gonna push the pressure closer to 190, and I'm gonna tighten up the LSA some more..

According to my 1/8th trapspeed, at my weight and elevation, my 367 is putting out 433 hp.
But IMO, that is not correct. The Wallace calculator does not know that I have a GVod that I use as a splitter. When I ran that trap I was using four ratios;
first, 1-od, second,and 2-od ; and the splits are .78-.80-.78. So my engine never falls into the hole that the 727 makes with a 1-2 split of 59%. It's kindof like running a CVT, the engine is always very close to peak-power. The Wallace has no way of knowing that, so it just spits a number out that it thinks it outta be, based on it's programming.
I don't know how much power my 367 is making, and frankly, I don't care... Because it is such a pleasure to drive as it is. It has the right amount of power, no matter what I'm doing, because it always has the right gearing.
I'm rambling now so
over and out
 
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If yur thinking like that, a low-deck 383 with a 440 crank, I think makes about a 425 cuber before boring.
but
A well built 383 is a screaming banshee. She is to BBs what the 340 was to the SBMs. At a factory stroke of 3.375 (compared to 3.315 for the 340) she can be a formidable hi-rpm weapon, without the monster torque associated with longer strokes. Torque which, in most A-bodies, just overwhelms the chassis.
The hick-up I anticipate is gearing such an engine for street. It won't take much to push that 383 to 400/450 horsepower, but it comes with the price of being at hi-rpm.
Nothing wrong with that except with 3.23s say, 5800 rpm with 28" tires is 58 mph.
To put the 383 power down where you mostly drive, say 35 mph is gonna be darn near impossible. And if you do gear it with say 3.91s, well then say goodbye to hiway cruising cuz 3.91s and 28s makes 65=3050 @ zeroslip, and that is not much fun, and usually uses a lot of gas to go anywhere. ..
So, IMO, if you do build to take advantage of the short stroke, you will want to consider a nuther gear for the transmission, an overdrive gear.
The A518 has a .69 od allowing you to turn ~2300 at 65 with 4.30s @ zero-slip. and the A518 has a low gear of 2.45, so 30mph@WOT will be about 4000 in first gear. In second 30 is about 2250@zero-slip. So that's kindof cool. You can be comfortably cruising along at 2250, and when you nail it, ZING! on the KD you are doing 4000, close to peak torque. First gear with 4.30s will rev the clock to 6000=45mph. On the shift, the Rs will drop to 3540, so whatever cam you choose, it better have the juice to pull you up outta that hole.
So now we have THREE data points to satisfy.
1) A first gear outshift at 6000, coming in at
2) 3540 in second at 45mph, and
3) A cruise rpm of 65=2300
Tuff call.
I suggest a solid lifter FLAT tappet cam , because;
A) that short stroke is gonna rapidly give up cylinder pressure with the kindof Intake closing angle that anything else will bring, and
B) you need an early closing intake angle to cruise at 2300 and get reasonable fuel economy, and oil-life
C) more importantly, you need a late opening exhaust to efficiently cruise at that 2300 number., and
D) the only way to satisfy all those requirements is with a solid FT cam.
So My choice is to have an after-lash Ica of say 64*, but I want an after-lash power duration of 110*. I do not care about overlap, Ok so
to be able to shift at 6000, she needs a cam to powerpeak at about 5300, so that would be an after-lash intake duration of 230/235 @.050
Allowing after-lash clearance ramps of 35*, that makes 265/270 intake duration.Lets use 268*after lash/232@.050, because this makes an off the shelf grind possible; the 268/276. Lets put it on a 110LSA,install it at 108, and the numbers come in at
268intake/118comp/110 power/276 exhaust/52 overlap; all are after lash numbers.
So now we are gonna need those aluminum heads and pump the pressure up to 11/1, and I get

Static compression ratio of 11:1.
Ica of 62*,
at 600 ft elevation
Effective stroke is 2.66 inches.
Your dynamic compression ratio is 8.88:1 .
Your dynamic cranking pressure is 184.06 PSI.
V/P (Volume to Pressure Index) is 167

BadaBoom! you got a tiger by the tail!, With flat-tops, a Tight-Q, and closed chamber alloy heads; suitable to be a Daily Driver, burning the cheapest gas money can buy.

>Can you make more power? Well sure; there is room in the build, but you will loose driveability.
>Can you get better fuel-economy? well sure; but it's gonna cost you performance.
>Do you need the overdrive? Only if you gotta hit the hiway at 65 mph. 4.30s are NOT hiway friendly; but they sure are fun in the city.
> do you need 4.30s? No, you can run less but then you will need more stall; about 200rpm per 10% smaller gear. and then your power peak moves up 10% per 10% gear change, so you might as well get a smaller cam; ~1 size per gearchange, but hang on, then your pressure is rising, and you gotta reduce the compression ratio, to keep the engine out of detonation.
> Everything is related to everything else; so once you set a course, IMO, you are more or less married to it.
> IF YOU STROKE it, NONE of this applys.
Happy HotRodding
Good googly moggly !! That was some serious writing !!! Yes was he said !! Good job Sir !!
 
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