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sweet70beast · 05-26-2007, 05:41 PM

When you say that you have a 350 trans now I assume that the 4 speed you mean is a 700R4. A 4 speed manuel would mean you would have to much to swap over and would not be worth it (no overdrive). The 700 swap is pretty straight forward, the yoke on your driveshaft will slide right in as the 700 has the same output as a TH350. The 700 is longer than a TH350 so the driveshaft will need to be shortened and the cross member will need to be moved back, I put a 700 in a 72 GMC 3/4ton a few years ago and the holes in the frame were already there. The 350 mount will bolt to the 700 as well. The column shifter will work with it too, it will just go past the 1 when you put it in low(the shifter will go down that far).

05-26-2007, 05:41 PM	#5
sweet70beast Registered User Join Date: Sep 2006 Location: Shelley Idaho Posts: 876	Re: 3 speed to 4 speed... When you say that you have a 350 trans now I assume that the 4 speed you mean is a 700R4. A 4 speed manuel would mean you would have to much to swap over and would not be worth it (no overdrive). The 700 swap is pretty straight forward, the yoke on your driveshaft will slide right in as the 700 has the same output as a TH350. The 700 is longer than a TH350 so the driveshaft will need to be shortened and the cross member will need to be moved back, I put a 700 in a 72 GMC 3/4ton a few years ago and the holes in the frame were already there. The 350 mount will bolt to the 700 as well. The column shifter will work with it too, it will just go past the 1 when you put it in low(the shifter will go down that far). Last edited by sweet70beast; 05-26-2007 at 05:42 PM.