The p-30 front springs don't seem useful for the 51 6400, I've done that comparison, the new ones are very much longer.

I had Eaton Detroit Spring make new ones for my 6400, in my case somewhat custom, but as stock was an option from them also.

Grigg

•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-