Older 904 to Newer la or magnum?

rumblefish360 said
So, behind at the crank is a 1.55 hole?

67 and older small blocks and /6's have the smaller 1.55" hole in the crank. 68 and up have a 1.81" pilot hole.

Ragtop I've seen the adapter ring on e-bay in the past but at the moment I ain't coming up with it. I'll keep looking