Rear axle conversion

[paperpusher]

Hi guys,

I have a 1965 chevy stepside that I'm restoring. I have a 350 smallblock to go in it. My question is, what gear ratio should I get to go in there, and what later model truck should I look to get it out of. Thanks for any and all input.

 

[Vin63]

I tend to approach this by answering a few questions: what size tire I plan to run (diameter mainly); what transmission type (gear splits and final drive ratio); what RPMs I plan on or want to run at a particular speed? Then I use some of the available online gear ratio calculators to determine what rear ring and pinion size best suits my combination.

 

[paperpusher]

Rear End Swap

I have a turbo 400 3spd for it, will probably be using size 18 or 19 tires. No hauling or towing. I have a spare rear end that the guy through in when I bought the truck. I pulled the 10 bolt cover off, and it was stamped 12-41 (3:42) ratio but it isn't a posi. I rotated one axle, and the opposite axle turned the other direction. I already bought the axle conversion kit with the adjustable trailing arm. You know the one where you have to weld on the u-bolt brackets. I want to go light to light,but I don't want the rpm way up if I do decide to jump on the expressway Thanks for your help.

 

[Vin63]

Here are some calculators that you may find useful.
http://www.wallaceracing.com/Calculators.htm