I'm thinking of doing this swap in my 73 as well, just have a few questions. My car has a 1976 360 small block and a 904 with a stall and aftermarket flexplate in it now.
All the 518s I'm finding are from 318 small blocks which I believe use different flex plates and stalls that won't work on my 360, is this correct? Should I keep looking for one hooked to a 360?
And will my linkage from the 904 slapstick work on the 518? Or do I need 727 linkage?