If you don't mind trimming the folded over edges off the frame where the radiator resides, and welding the seem back up, I will give you the part # of the biggest rad that will fit in there and the fans. I managed to get my iron block 605 Hemi to cool on the street finally.

Your really going to try and hook all that motor on 275's?

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk