63Custom, Before you take Bent and my advice on the rear axle do some home work. Assuming from your handle that your truck is custom decide what tires you are going to run, find out what their diameter is. What engine are going to have. Will the tranny have an overdrive. When you have a fair idea of where your going, then find RPM calculator on the web. The RPM calculator will allow to input Tire dia., rear axle ratio, mph and get RPM or switch RPM for mph and get rear axle ratio. may of not got tha quite right. I don't have one bookmarked at the moment or I'd add it. The object is to find rpms in the bottom half of your torque curve. Then you tell the rear end shop and tell, them what you think you want and why. They may have a few suggestion and prices. The other option would be to look for used rear axle. Do a search in the archives rear axles should come up quite often. Swapping rear axles can get messy, rear axle width, coil springs or leaf springs, shock mounts. panhard bar, get the right width and swap mounts. Lots to think about. An overdrive will let you compromise a bit for street and highway performance. That's a start. I changed the rear axle in my 68 C20 from 4:56 to 3:73 out of a 73 C20 or 30 with a BB and automatic. It was almost a direct swap till I got to the shocks. GM went from both shocks going forward in 68 to one going back and one forward in 73. My mpg increased by about 20%
Larry
