With milodon pan i cannot use the gm original main bolts, so i bought arp 135-5201 main bolts and found out that the arp bolts are 0.150" shorter compared to gm bolts, I quess this is not a problem? Arp only lists this kit for gen IV/gen V.

The 0.400" loft is pretty good. Exhaust doesn't choke off at higher lift/flow. They should make some good power. What seats did you end up using?

Have to to ask about the seat angles. Quess that the 650-675hp might be possible. Now i try to decide what icl i instal the cam.

My bad...was looking to see what metal style of seats you used. Powdered metal?

Yes, powdered metal

Starting to steer away from these arp bolts. How many threads should be engaged in the block? I know the old rule for depth is the thicknes of the bolt, but i am barely there with these.

Jani,

Conventional wisdom holds that 1-1/2 X thread diameter will achieve maximum thread strength. Personally, I like as much as I can get, and have designed parts with 2-1/2 to 3 X thread diameter, just to make myself feel better about them. I haven't the foggiest on head bolts, but I'd think you'd want considerably more thread engagement than single thread diameter.

Thanks. Brad.

Put studs in.

Do i need to line hone the mains then?

you should