I ended up going with the koyo radiator for my 71, thought I would share the install with everyone.
I cut and tacked up (mig on the inside) a small shroud and had it tig welded by professionals
went with a16"' flex a lite fan
Went to napa and got a #9069 hose for large gm trucks (see the oem's have crossovers too) and cut out the J part and used that for the upper hose.
The bottom hoses are a 2.25" 90 on the radiator side with a 2.5" connector jammed into it, and a 2.5" 90 hose from there to the RB. Came out pretty good ,cars not done yet so couldnt tell ya how it works.
front view