Also,
You will certainly have the power, do you have plans for good brakes and reliable steering? (edit) I see you have newer axles with disc brakes up front! What are they from?

To make the best of the swap you will also need to change your rear axle gears so you can efficiently drive the speed you want.
rule of thumb is engine peak torque rpm, or just faster, is the rpm you want to be at when in high gear on the highway at your preferred speed. I like this calculator http://www.onlineconversion.com/bigger_tires.htm
What transmission will you run? did you get the Allison, and is it the 5 or 6 speed? the 5 speed can be reprogrammed to be a 6 (extra overdrive) no parts needed.

Grigg

Last edited by Grigg; 03/20/2008 2:44 AM.
•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-