I know that one of the major issues killing the performance of my engine is the heads. They are cast iron 202/160 with 76cc chambers (#883). I recently came accross a set of casting# 8917291 that have be reworked with 202/160 valves and 64cc chambers. With the current heads I'm at about 9:1 compression. My question is ..... would swapping out to 64 cc heads do anything for me?

Thanks
Chris

Sorry ... my existing heads are #881

Yes, swapping to a smaller head chamber, will raise your compression ratio. Without knowing what you have for pistons, I would estimate your compression to around 11:1 ?

I've got KB flat top pistons.
Also found a set of Camel Hump #461 with 62 cc chambers??

Chris,

There is a good chance that the -291's with big valves installed will flow less than the stock medium valve heads unless they have been plunge-cut relieved on both valves like stock big valve double-hump heads.

And flat-top pistons a stock, down-in-the-hole, of about .025" and .020" thick shim headgaskets will put you right at 10 to 1 with 64 cc chamber heads just like the old 295 and 300hp/350's are.

pdq67

Anyone think the 64cc swap is a good poor man's performance upgrade?
They've been rebuilt with the 202/160 valves and never been put on an engine. Been sitting for 3 years in a garage and letting them go for $500 obo.

I ask because I don't have the money for a nice "top end kit".

882s maybe? $500.00 for old school heads no.Save your money and buy a set of new aftermarket heads.The 882s flow almost as well as the hump heads.I would say 20 to 30 hp gain at best for $600 spent. Depending on the rest of your combo 10 to 1 may be to much comp. to run on pump gas.

Sorry for all the stupid questions guys. I got completely hosed 4+ years ago with my engine. Bought an advertised 350hp engine and ended up with about 250 hp ( 205 and the wheels after a dyno session ). First project car and didn't know any better. So I'm trying to get the best "bang" increase I can get on an extreme budget. The cam specs are: Crower, Intake Dur. 270, Exhaust Dur. 276, Lift .456, Rocker arms are 1.5 roller tip. With that in mind, if aftermarket heads aren't an option right now, are there any other head swaps out there that can give me more?? As I said above. Right now the heads are #881 with 202/160 and 76 cc. About 9:1

Thanks for any additional input

Yes, double-humps are always good bang for the buck even tho there are better heads out there now for the money.

Have the -291's been plunge-cut??

If they are, use them and you WILL BE FINE, imho!!

pdq67

Do some more shopping. A few years ago, I picked up a set of fresh used Dart Iron Eagle 180's from a member here for $650, did a krylon rebuild and bolted em up. The iron eagles, or World s/r torquers or other aftermarket iron heads flow a LOT more than any 60's casting, and they are readily available used and don't cost that much new.

another option would be vortec's. Go boneyard shopping, bet you could cop a set of vortecs and thier valve covers off a 90's truck for near free, buy a manifold ( and sell the one you have now) and you're good to go. your .456" lift should work with a stock vortec.

Thanks Jim ...
If I am able to find the kind of heads your talking about after a while. What kind of HP do you think I "could" be looking at? I know it's all guess work at this point, but if you could through a ballpark figure out there going from 9:1 with 76cc to ... 64 cc or so with the cam I've got?? Supposedly 250 at the crank right now.

I don't do the "guessing at numbers" game... but the power difference when I swapped my heads was "tremendous." I did start from a worse place than you tho, someone had put "nailvalve" 327-210 heads on my car!

Still, useable rpm went way up, and power and torque way up from idle to redline.

I'm pretty well convinced that good heads are the best thing to give any motor, and that modern casings work much better than old stuff, even without being that much "bigger" due to better shaped combustion chambers and ports that flow better without really being "bigger".

Thanks very much for the input.
I'll be doing some hunting.

Chris