MichiMike

Make sure it's gen 6 502

BBYSTWY

How can I tell that by looking at it??

JRider

iTrader: (1)

Why is that? They do not have fuel pump provision.

dereknkathy

All heads interchange, except for the 8.1, gen 7, 8100 vortec block. That design added the 2 missing head bolts that would hafta go through the intake ports. Gen 5 and 6 both have no fuel pump mount. Gen 5 has 10 bolt timing cover. Gen 6 has 6 bolt. Gen 6 is machined for factory roller lifters and dogbones. Gen 5 is flat tappett. Roller conversion is very little problem. If it is a cheap 502, it'll be a gen 5 ...

BBYSTWY

I gotcha...think I have it figured out...502 long block AFR heads 6-71 rebuilt GMC blower 7 lbs of boost..should be interesting!!



Stewart

Griff

The amount of boost you run safely is dependent on the static comp ratio and fuel octane you intend to run.
With an 8.5 CR and 6# of boost, you're about maxed for 92 octane.
http://documents.holley.com/techlibr..._tech_info.pdf

BBYSTWY

I run premium 93 octane in it already so that's what ill continue to run...I don't think you can even buy 92 around here lol..I know its only one point but I see what you're saying....thanks for that tidbit!! something I would have overlooked for sure

Stewart

MichiMike

Don't the Afr heads have steel valve seats that suck ass. I remember reading that somewhere and seats should be changed. Anyone?

MILD THUNDER

iTrader: (3)

They do in fact come with a standard ductile iron seat. Darts marine heads, GM/merc heads, engine quest heads, and Afr's bought from teague marine with their service performed, have powdered metal, sintered, upgraded seats to hold up to the abuse of marine environment . The very early merc 565s were recalled , as they found the standard seats they used werent holding up. Some guys say the standard seat is fine. Guess it depends what you want out of them. I know of quite a few oso members who pulled their engines down with low hours and had excessive exhaust valve seat erosion with the afr heads.

BBYSTWY

I switched directions again as far as where I'm getting heads...going with af racing...talked to Alan there and I'm pretty sure he addresses the seat issue...he's been following this thread so he can correct me if I'm wrong

good into tho guys thanks!!

stewart