Chevy 350 in a 1978 Buick Skylark?

[L67ss]

my own experience and a 2004r says top four are different

 

[L67ss]

yellow is holes used by bop and blue is holes used by chevy

 

[L67ss]

Back when I still had an olds in my car I was eating 200cs like candy. My moms bf tried telling me the Chevy th350 I had would bolt right up. So I dropped the trans and compared bellhousings up against each other. Only the two bottom bolts and the alignment dowel hole lined up​

 

[565bbchevy]

Here is the Chevy to BOP trans adapter these are for 350, 400 and 700r4 trans.
The 2 holes on top with welded nuts are for the the 2 holes that don't match the BOP trans the other 6 are for the Chevy and obviously the 2 larger holes are for the alignment pins

 

[L67ss]

Reason they left out the middle bolts is in order to have enough material to have a threaded hole it would likely interfere with the flex plate

 

[L67ss]

If the bop trans woulda bolted to a Chevy I would have been able to sell the three bop th400s I had ten years ago instead of giving them to scrappers

 

[L67ss]

Hold on I have a side by side pic

 

[L67ss]

 

[L67ss]

I had a friend get creative with rocker arms on a regal he traded in lol

 

[565bbchevy]

I just looked at the instructions for the brand adapter I used back then which was TCI and yes they use 6 bolts to mount the adapter to the engine but only 4 bolts for the BOP trans (the upper and lower) all the more reason I wouldn't use it in a performance application but does work fine for stock to mild applications.