What numbers are stamped on the air horn??? Post them here and I may be able to look it up.
Master ASE Certified L1 Chrysler Technician- still a Ford fan at heart.
1964 Thunderbird Hardtop- Chantily Beige- 390 FE 4V V8-Uncle's Car
1966 Thunderbird Convertible- Red- 390 FE 4V V8- Uncle's other car- waiting for paint and body work!!!
the 6210 I believe is a 650 spread bore most lilely used on hipo chevys such as 327 to the 402 from '65 to '70. The square bore of the 750 won't match up. I've only known holley to make only two spread bores....650 and 850