so im lookin to do a head swap and im on the hunt for heads now. My motor is from a 91 camaro and im runnin the stock cast iron heads now. The motor was rebuilt and blue printed when i bought it and i have since added all the boltons and a bigger cam. I have been told by the builder that the CR is 9.6-1 now if i go with the new AFR 180cc eliminator heads and had them milled to 58cc how much would this raise my comp ratio and would this be a good idea? Also when you have the heads milled how does this affect the flow numbers on the heads?

 

What engine specs can you provide?
After rebuilding and blueprinting you should have info on:
Piston deck height,
Piston part number,
Cam specs and installation specs ( straight up or... ),
Current cylinder head casting number and head gasket specs ( to double check the 9.6:1 calculation).

From that info you can zero on whether the AFR's are your best bet.
Milling your heads won't affect flow.

 

with the man above.
and dont 58 cc heads fit a 305?
i know that 601 stock heads on a 305 will get the compression up to 10 to 1 but you have to be way above that with 58 cc heads.
but you will need to give us type of pistons, etc.

 

ok, i have looked back on the paper work i got from the builder and i dont have much of the info your lookin for but ill do my best. The heads are the stock 91 camaro iron heads, and the head gasket is a factory replacement "what ever that would be" The motor is .40 over with a cylinder clearance of 4.0399 to 4.0404. pistons are seal power hypert flat tops "dont have a part#".....the cam is a comp cams xr264hr-10 specs 212-218@.050 264-270, 110, lift is .487-.495 but im runnin 1.52s for lift is a lil more. as for the installation on the cam im not sure...i had a fleet service shop do the new cam install "my dad knows the owner" and im sure they prob installed it strait up. i have red in the comp cams camshaft installation & degreeing instructions and it says the cam has 4 deg adv grind into it and its best this way for street performance. I wish i knew more...

 

In theory you'd be around 10.2:1, and with such a small cam, that might be pushing your luck with pump gas. The AFRs would show a power increase even if you didn't mill them, but even milled, they'll still far outperform any other 180cc heads. Slap them on!

 

With the info you've provided and what I can find and/or assume:
350/4.04 bore/3.48 stroke.
L98 cast iron heads; 64 cc.
Factory replacement head gasket; .039 x 4.10.
Sealed Power hypereutectic flat top pistons: 5 cc valve relief.
.025" piston below deck.
9.84:1. You would have to measure everything to be precise. I suspect that to be estimated on the high side.

 

Hi Folks
the stock L98 has a compression ratio of 9.5-1 with 64 cc heads - going to a 58c head would give you about 10.2-1 compression ratio.
thanks
Bill

 

is 10.2-1 to much for 91-92 gas? arnt the l-98 cortvettes "113" heads 58cc? there cam is much smaller then the cam in runnin now. Plus im lookin to also do a cam swap down the road to like a 218-224 or 224-230. how would the 180cc AFRs run with these cams?

the reaosn i was askin about the 58cc is because the heads im lookin at have already been milled to 58cc...there brand new 1800cc afrs for 1200$ shipped do you think this is a good deal and a good head to get for my setup?

 

Hi
On my 92, Edelbrock (60CC) heads were cut .010 and runs on 93 ok, my 2002 Z-28 SS (LS1 more like an LS6++) has compression ratio of 11.2:1 and runs on 93 OK. I don't believe you will have any issues.
thanks
Bill