Our 78 Magnum GT Found

rumblefish360 said
@RustyRatRod - 9-1/4? 3.23 or the 3.55 option.
(IIRC)

I'm sure it was a 3.23 or numerically lower. It didn't have much RPM at highway speed. It did have 275 60s on the back, though. It would liquefy them when I got done with it.