Has anyone seen the type bolt at the far right of this pic? Original or something else? The other two look right for 70-71 340s. The odd one has a 3/4” head. Wondering if it might be from a 273 motor?

Looks similar to this adapter bolt

https://board.moparts.org/ubbthread...all-block-oil-filter-adaptor.html#UNREAD

I used to hit the U Pull It and pulled 2 at diff times off early A Bodies with the small head bolt like that.
But we're cast iron adapters not aluminium. The stock 1972 340 Challenger I was 3rd owner of and knew the other 2 owners had one on it it was aluminium with large head bolt.
All the 70 up ones I pulled were large bolt head even the FMJ ones were large bolt.
Note the F, M And J Body ones are different looking bodies but same large.head bolts.
Steel Wheels, disk brakes and 90 degree oil adapters and 8 3/4 sure grips were my go to easy grabs at the U Pull It so saw a good bit of them.