If it is the original rearend you can look at the door tag if it's orig & see what ratio you have ,,,code under ''axle''. rear may have a tag on one of the nuts also. probably 300;1 or 280;1. I have 3;50's in mine with a 1:1 final drive 4sp & rural hwy's @ 55 mph aren't too bad. but 70-80 is humming up to 3000 to 3500 so 355's would be pretty good with your taller 5th gear.
Does your first gear seem a little high geared?
63, ladder bars, coil overs.....
Re: 63, ladder bars, coil overs.....
Seems like first gear is low to me, I'm not sure what it actually is. I'll check the tag. I think it's the original, but then again could be anything knowing the guy I got it from. He said he thought it was a 3.20?