[Purestock26]

Just wondering what this forum thinks is a good head to run on a purestock dirt track car.

Rules for heads are:
Stock oe type head (no vortecs) if they can't cross referance # = diqualified!!
no porting/polishing
must have a minimum 72 cc chamber
max valves 2.02in/1.60exh
stock type springs (no behive)
Stock rockers

Fed by:
Stock 4 barel duel plane intake
500 cfm rochester 2 jet. (max is 500cfm and no holly's)
.450in/.450exh cam (spec cam for dirt track racing) .450 lift max

Exhaust:
stock manifolds. (no center dumps)

Bottom end:
Stock crank, rods (350) Rules
.030 flat top pistons with 2 valve relief

The motor we have in one car has 993's on it but im unable to locate another good set. I was looking at 882's but have heard that they are prone to cracking. I don't realy know what other heads would work. Any thoughts? Would 882's work for my application?

[Rhansen]

these ar supposed to be a direct replacement for the 487x head. Should be legal to run them
http://www.aamidwest.com/Enginequest...nder_Head.html

[Purestock26]

I would love to run an after market head but have seen others diqualified for using them. Our rules were locked in for 3 years. We are stuck untill we can review them in 2014. Here is a coppy of what the rules state for our engines:

ENGINES: 4, 6 or 8 cyl., small or big block. Entire engine MUST remain OEM stock, small block Chevy 327,350, or 400 must use
a cylinder head with a minimum of 72cc, 1 cc tolerance. ONLY a GM motor allowed in a GM car, Ford in a Ford, Mopar in Mopar
etc. Max. overbore .060 Max. 9.5 to 1 compression. NO MODIFICATIONS TO ENHANCE HORSEPOWER.
NO Vortec ! NO Magnum! NO Boss heads! Air conditioning, alternator, pollution devices and heater may be removed. NO engine
setback allowed. Engine MUST remain in stock OEM location. NO racing or high performance parts allowed unless specified. Max
flat top piston cannot go past top of the block. Maximum cam lift; intake/exhaust is .450 inches
including stock rocker ratio. Hydraulic cams ONLY. NO roller rockers/lifters. NO aluminum intakes, heads or blocks. Cast iron
exhaust manifolds ONLY. NO center dumps or factory tuned manifolds. Vortec exhaust manifolds allowed. Stock type ignition
system for that make of car ONLY.
4.1 NO POLY locks on rocker studs!
4.2 NO hex head or screw in rocker studs! (May be pinned)
4.3 NO guide plates on rocker studs!

Any thoughts?

[Rhansen]

If you are positive that you can't run these.....

Part #CH350I is a direct stock replacement for the Chevy 350 cylinder head with 167cc intake runners and 76cc combustion chambers, 1.94 intake valves and 1.50 exhaust valves.

then it sounds like you might be in for some 'fun' trying to find a decent set of oem heads. Not all the 882s are lightweight castings (look for early ones) and I have read that they are as good as the 993 but the intake ports on the 993 look better to me......

[Purestock26]

I have been looking for 993's for 2 months now. I found one set but im not going to pay 800 and still have to rebuild them. Im told that the 882's flow about the same so im thinking that is the way im going to have to go. You know of a way to tell the early ones from the later? Heavy casting around head bolts?

[Rhansen]

Originally Posted by Purestock26

You know of a way to tell the early ones from the later? Heavy casting around head bolts?

IIRC thats right. The lightweight ones have a 'scalloped' appearance on the exhaust side.
why so much for the 993s? I wouldn't give more than $50 for them, which btw is how much I sold my last set of 882s for......

[Purestock26]

Good to know. Thanks for the help. My serch continues......

[nialkc]

Remember your really interested in torque. Not high rpms (HP) You will probably not turn over 5500 or so. The 70s big eng OLDS,Pont, Buick all used 500cfm carbs, some trucks also. these flow the same as the holley 500. I would use the thin steel head gasket also. It will give you about 1/3 point compression. Must be careful about torquing the gaskets. use the minimum allowed combustion chamber volume. Be real careful with your value seat position. Keep it as high in the chamber as possible and as narrow as you dare. .060 would hold up well in your case. How well a particular casting flows will not be important to you because you wont see the RPM that will max your heads anyway. concentrate on low and midrange Torque . It is what will get your car off the corners and that is what wins races Hope this helps PS if you can run a 400 cube eng I would DEFINITELY do so. Nial

[Purestock26]

We can run a 454 bigh block if we wanted. Some have tryed but you cant get through the corner. Pushes like a dump truck. If a 350 runs out of steam around 5500 wouldn't a 400 run out sooner? one car has a 400 and doesn't seem to do as well as th 350's. Maybe he can't drive? With our corners we usualy see a 1000-1300 rpm drop. Our ideal range is 5500-5800 rpm max. Some are pushing 6000 into the corner but you can tell they are running out of power. With the other car we see the 5800 rpm and it is still pulling quite hard. On a good night we can get the cars up to 80mph entering the corner. Average is about 75mph. Thanks again for the help.

[F-BIRD'88]

The best of the larger chamber SBC heads are the 441 441X 487(X). the 336(x) and the 920's are not too bad also. ALL the 882's suck Very bad restricted exhaust port. Small intake port.
The 882 head flow #S you heard about are BS. The 882's and 624's are the worst of the worst.

You cannot "port" them but you can do a beauty multi angle valve job and a bowl hog for the larger valves. it just has to appear stock like.
deck the block but protect the serial numbers on the deck to keep it legal.
use a thin .015" gasket

Isky has some good .450" dirt oval cams for you.
advance as required to get torque and cylinder pressure.
Isky 235D springs drill and roll pin the rocker studs.
www.iskycams.com

[BigEd36]

Howards Cams also has a good number of .450" lift rule cams.

[hpete]

Build as strong of a bottom end as you can. The difference in lap times between stock 993's or 882s or any other 350 head is zippo. Spend your money in the corners.

[6426yy]

Purestock, where do you live I've got some stock heads I'll give ya, they need rebuild of course but $800 for 993's is crazy. I've got a fresh set on my pickup right now and I'll pull em off for half that!