So I was researching what my car originally had with the build sheet and what I have now. The transmission (original serial number), intake, and head numbers look correct. I'm getting mixed results with some websites on the engine. Maybe you all can help. Here's what I have on the 1968 GTO auto 400.
YS Engine (not matching serial but correct year) is casting number 9790071 with a date Sep 27th 1967 (I277). Some sites say 400 HO, others say normal 400 at 350HP. Any idea?
I do have 16 heads dated Nov 1st 1967(RH) and Dec 30 1967(LH) which one place says 2.11/1.77 HO. I also have LH manifold casting 9791637 which I found to be LH 400 D-Port GTO Ram Air 3 manifold. The RH manifold looks the same but no numbers.
Thanks for any help.