Deck Clearance: .0038 (above block) that would make it a negative deck clearance?
With a piston valve relief = 0cc (no valve reliefs) I get exactly 8.0:1 compression ratio – which is what my shop manual says it should be (8.0:1) for a 350 2 bbl but doesn’t list for a 350 4 bbl… All the articles and books I’ve ever read claim the 74 GTO had a 7.6:1 compression ratio. – Adam Womack • The ’46’ is cast onto the heads on the 74 GTO. I’ve heard it described as cast on a pad on the head between the exhaust ports. I think on a clean non-corroded head, you can see that the head has a slightly raised and flat pad/square/rectangle with the 46 cast on top of this thin pad. To the best of my knowledge, the 74 GTO head is the only 46 head produced in 74 with screw-in studs. All other 46 heads in 74 had pressed in studs. I believe there was another 46 screw-in stud head but I think it was produced in maybe ’68 so checking date codes will eliminate this head.
