I would suggest calling A-1, and order a 8 inch converter. I have a 8 inch tight 4800 RPM stall converter in my 505 stoker, with 4:10 dana. Nothing but fun, works so nice, perfect drivability on the street, no slop. Stomp on the gas and holy crap, it flashes to 4800 in an instant and takes off. Very good product, no complaints, custom made per my dyno sheet, and car specs. May be a little more $$ than some, but is worth it in my opinion. Give them a call, you won't be disappointed. Very nice guys to talk with also.
FYI...Dave Smith at Pro-Trans built my 727, and recommended that I order a 8 inch A-1 converter. I trusted his recommendation, glad I did.

https://www.a-1perf.com/