Does anyone know off hand what years interchange for small block Olds valve covers?
Also which engines interchange?
I'm pretty sure I already know the answer to the second question, but I'd rather get it verified.
I'm trying to find which covers I can look at for my '84 307

 

all valve covers from the 307 350 400 403 425 and 455 will work

 

Short answer - all of them (1964-1990). Olds did delete five of the ten bolts on each valve cover in the 1980s (must've saved 5 cents per car!), but you can still use the early covers on late heads and vice versa. The five bolt covers even still have the blanked-off locations for the other five bolt holes.

 

Thanks guys. I figured that was the case but wasn't sure. I knew nothing about the 10 vs 5 bolt thing though. That would have confused me at some point if you didn't point it out.

Olds are so much easier than the Chevies when it comes to this stuff.

 

huh?

 

Chevies aren't as interchangable. The gen 1 and 2 engines don't swap many parts between them. The gen 3's don't swap anything with 1's or 2's. Then there are the centerbolt vs perimeter covers and 1 or 2 piece rear seals which make other parts not swappable within their own generation. Then there's the self aligning vs non aligning rockers which aren't swappable. Nothing from big blocks swap into small blocks other than power steering pumps and alternators.

It seems like pretty much every Olds engine can swap every part other than the crank/rods/pistons. To me that's easy

 

About the time the "windowed main web" blocks came out they went to this 5 bolt valve cover arrangement, as well as larger head bolts, less nickle content, and provisions for A.I.R. lines in the heads.

 

I've heard that is a myth. I think one of our members was going to investigate it but I don't recall if he ever got any concrete information.

 

Um, my 1966 442 with California emissions came from the factory with A.I.R.. Thats's why every Olds head cast from the 1966 model year onward has the dreaded A.I.R. bumps in the exhaust ports. Most of them are not drilled, however.