[pittbull7934]

I have a 383 stroker, on another thread I was alerted to the fact that my heads are not the best heads for my motor. I was told that is why my hp and torque numbers are so low (for a 383). With what I have listed below is there any way to figure out what heads would be best for my motor and what kind of gains i could expect, if i put new heads on? I plan on driving it more than i plan on taking it to the track so i will need heads that are street heads. I am also on a limited budget.

Any and all suggestions and recomendations are appreciated. The specs I have on the motor are listed below.

The rods are 5.700 stroke (a little longer) Molly rings with forged flattop pistons, the whole bottom end was balanced.

The heads are from a 350 engine they have had a 3 angle grind job on them, and had stronger over sized valves installed with bigger springs for a higher lift cam. Up to 540 lift. Manley valves 2.02 intake valves 1.60 exhaust valves. The cc of the head i believe are 68 which would make the compression ratio 9.7:1.

Crower cam grind: 288hdp lobe center 112 intake 288 exhaust 296 duration @ .050 intake 234 exhaust 246 gross lift .497 .504 crower hyd lifters and single springs for the cam crower aluminum roller rocker arms ARP stud kits for heads and journals ARP bolt kits for everything else (intake, exhaust, carb, timing cover ect ect).

High flow oil pump with extra volume oil pan ( i think it takes 8 qts)

edelbrock timing adjustable timing chain.

edelbrock performer RPM air gap manifold

Accel HEI distributer with HEI unit

Accel 8.8mm racing wires

363.6 HP @5200
407.5 torque @4000

[Deez]

The heads are from a 350 engine they have had a 3 angle grind job on them, and had stronger over sized valves installed with bigger springs for a higher lift cam. Up to 540 lift. Manley valves 2.02 intake valves 1.60 exhaust valves. The cc of the head i believe are 68 which would make the compression ratio 9.7:1.

They have a casting number on them, you need to find it. But most any aftermarket head will get you more lunch. What you have sounds good as far as stock head parts - sounds like somebody spent a few bucks, probably close to some new heads. Find out what you have, for sure, and maybe you can fetch some dough for them for what they are to use toward new. In any case, aftermarket will put you miles ahead provided you don't opt for those el cheapos - what you have will more than likely outperform them knock off heads anyway. What kind of coin you looking to drop? If you went with a known power making head, you might pick up close to 100 HP+ everything else the same. Also, your 5.7 rods are not longer unless you had short 400 rods or are using like a 5.85.

[techinspector1]

With flat-top pistons and 68cc heads on a 383, your static compression ratio is around 10.4, not 9.7. That's ok, because you have enough cam to cover it, but if you go to 64cc heads, the static compression ratio will jump to 11.0 and you may not be able to feed the motor with pump gas without it detonating.

Your power numbers stink. Anyone who can't make 500 horsepower and 500 ft/lbs with a 383....ain't tryin' very hard.

Save up for a set of AFR180 heads with 65cc chambers. That will give you a 10.75:1 static compression ratio that will work better with the cam you have and the aluminum heads. With an 850 carb and the rest of what you have, the motor will make 522 hp @6000 and 511 ft/lbs @4500.

[pittbull7934]

Originally Posted by Deez

They have a casting number on them, you need to find it. But most any aftermarket head will get you more lunch. What you have sounds good as far as stock head parts - sounds like somebody spent a few bucks, probably close to some new heads. Find out what you have, for sure, and maybe you can fetch some dough for them for what they are to use toward new. In any case, aftermarket will put you miles ahead provided you don't opt for those el cheapos - what you have will more than likely outperform them knock off heads anyway. What kind of coin you looking to drop? If you went with a known power making head, you might pick up close to 100 HP+ everything else the same. Also, your 5.7 rods are not longer unless you had short 400 rods or are using like a 5.85.

the casting number on the heads is 3973487.

I am aware the aftermarket heads will give me an increase, but what i was wondering was what kind of numbers i should look at for the he heads. and with those heads what numbers could i expect.

I looking to spend under 1000.00

[pittbull7934]

Originally Posted by techinspector1

With flat-top pistons and 68cc heads on a 383, your static compression ratio is around 10.4, not 9.7. That's ok, because you have enough cam to cover it, but if you go to 64cc heads, the static compression ratio will jump to 11.0 and you may not be able to feed the motor with pump gas without it detonating.

Your power numbers stink. Anyone who can't make 500 horsepower and 500 ft/lbs with a 383....ain't tryin' very hard.

i know my power numbers stink, thats why i am here

i DO NOT want to have to run high octane in my car. I have already had that expierence and it is one i do not want to repeat.

[techinspector1]

I added another paragraph to post 3, but you won't buy 'em for $1000.

[pittbull7934]

Originally Posted by techinspector1

I added another paragraph to post 3, but you won't buy 'em for $1000.

thanks! so do i want to get 65cc heads is that what will make the difference. I am not to savy when it comes to numbers with heads.

if i find a name brand set of 65cc heads will that help? or are there other factors that contribute to the numbers you mentioned? to tell you the truth those numbers are what i would like achieve.

[Deez]

No, he'll buy 'em for more, and post back how happy he is. I'd go for the 195s because they'll work for when you're ready for more.

Dude, just don't cheap out on heads, it's where you'll find what's missing.

[pittbull7934]

what brands are good? are there other numbers besides the chamber size i want to look at? i noticed the afr's on ebay for 1500 is that a good price? also they have the 195 cc/ 65cc heads what is the difference beteen those and the 180cc/ 65cc heads?

also this motor is going in a 68 el camino, i think i will have traction issues with the already low numbers i am running.

it has a turbo 350. and i set up the rear end up with a 1 inch sway bar and adjustable tubular upper control arms and tubular lower control arms. new springs, new air shocks and new poly urithane bushings.

i have 255's but i think i will have to go with more narrow tires.

i was raised working on old cars, but when it comes to specs i am dumb and need help. im in law school now so i dont have allot time to spend figuring out all the cool spec stuff. thats why i am here. thanks so much guys i appreciate it! but more detailed feedback would be appreciated.

[Jsup]

You can do Brodix IKs for under $1000. The 200CC runners made 568 HP here:
http://brodix.com/heads/ikdyno.html

You can see the specs there.

They'd be a good head if you want more. They can grow with you.

Brodix is one of the oldest, most respected manufacturers in the business. They own their own foundry and have the best QC in the industry by many standards.

If you want to spend $500 more there's more choices, but for the $1000 mark, these are an excellent head.

[ap72]

Buy a bare set of heads and swap your parts over, if the springs aren't fatigued that can save you some coin right there.

For some good budget castings look at RHS, Dart, Brodix, even GMPP has some decent heads if you want to to that route. You'll want a 200cc intake runner or so, also a little port work goes a long way in most of these heads, you can get over 600 horses out of them if you have some skill.

[Jsup]

Originally Posted by ap72

Buy a bare set of heads and swap your parts over, if the springs aren't fatigued that can save you some coin right there.

For some good budget castings look at RHS, Dart, Brodix, even GMPP has some decent heads if you want to to that route. You'll want a 200cc intake runner or so, also a little port work goes a long way in most of these heads, you can get over 600 horses out of them if you have some skill.

Good idea on swapping the hardware. You can get the cost down to under $800 if you do that. Springs are cheap. Keep the vavles do the springs. A set of LT-4 springs which should be plenty is about $30. Springs are like sparkplugs, old ones don't run as nice as new ones.

Don't take this the wrong way, the castings mentioned may be cheaper, but they are not CHEAP. All of them have some very fine results in their castings.

You can pick up a set of any of those heads in the $5000 range. What you're getting if you do go this route, is top quality castings that you can build on. I guess my point is they may be budget, but that does not equate to poor quality, in this case. The more expensive solutions will not be better quality I guess is the point.

[ap72]

not to be nit picky, but I think Jsup meant $500, not $5000... most of us realize that but some new guys may not. And I would actaully say its about $800 or less for a good bare set but it all depends on what you're looking at, some can be had for $500.

[Jsup]

Originally Posted by ap72

not to be nit picky, but I think Jsup meant $500, not $5000... most of us realize that but some new guys may not. And I would actaully say its about $800 or less for a good bare set but it all depends on what you're looking at, some can be had for $500.

Sorry, AP, meant $5000. My point was that the castings your getting for $800 are the same quality as the ones you're getting for $5000 that there's no degradation of quality because of price. It's a matter of finish. The $5000 cantered valved fully ported version comes from the same factory, with the same QC procedures as the $800 bare castings.

I didn't want to leave the impression that any of those you mentioned were somehow inferior just because you choose the entry level product.

[ap72]

I thought you were speaking of the original bare castings, when you gave the price, not the fully worked over complete version.

But you are right, they start with the same castings.