The 1231786 is a 70 455 head. It could be either a std 455 head or a stage 1 head. The head cast "S1" is an over the counter head from the parts dept. The third pic are stage 1 valves
Sweet! So I scored a set of stage 1 heads? Is the service head a 70? Here is a picture of the valves and combustion chambers from both part numbered heads.
That casting number shows correct for 1970 and 1971. See http://gasalley.thetumbleweeds.net/tech_archive/buick/heads.htm Devon
I could be mistaken but I seem to recall reading that big valve heads did not have the unshrouding and stage 1 heads did
They were free. The same guy called again today and said he found another set in his shop that I can have. The heads came with a complete shortblock engine and intake manifold also.
There is a difference between big valve heads and big valve unshrouded heads. The big valve shrouded heads can be unshrouded by a competent machine shop.
I like to start with a small valve head and machine them properly,but if those a free,and they are good,can’t complain about that.
If they are 70 heads or even 71 heads, it looks to be they have aluminum rockers. I thought they went to stamped steel ones?
Huh.. Maby they changed to steel mid year or they came out in 71? I swear ever stock 70 head iv'e scene has the steel ones. I just looked at my Max per Buick Engine book and it mentioned after 69 they went to 1.55 steel rockers. Wondering if your heads were worked on or put on a 430 block and kept the 69 oiling? I am no expert though.
Wrong info in that book,....aluminum rockers didn't come into production till very late 71 and the full production in 72,..of you see a 1786 or 7661 head with steel rockers they were replaced
Yep, '70-'71 heads but they look like service replacements. That means that somewhere along the way, the first generation 455 aluminum rocker arms may have made their way onto these replacement heads. First gen 455 aluminum rockers are not to be confused with '67-'69 aluminum 400-430 rockers, completely different design and oiling strategy. The first gen 455 aluminum rocker arms oiled through the pushrod, and all later 455 rockers did the same, but with stamped steel rocker arms. Devon