'72 C-10 3-Speed to 4-Speed Swap?
 

I've got the original 3-Speed Trans in my '72 C-10, which I believe is a Saginaw (looking to verify this), which has a 2.85 1st. The truck has 3.73 Rears and I put extra tall tires on the back to off set the low gear. I'm looking at a 4-Speed Saginaw which has a 3.50 1st. This would give me a much better 1st gear plus an extra gear to boot.

I'm more familair with Muncies, but my question is what do you all think of the 4-Speed Saginaw for an everyday truck? and will it be a direct swap, driveshaft and all?

Any info would be appreciated.

Bill

Re: '72 C-10 3-Speed to 4-Speed Swap?
 

Use the input bearing retainer from the 3 spd(to give the proper pilot size in the bell), & nut & bolt the bottom 2 ears on the trans.....otherwise its a bolt in. I have run that trans in a couple trucks, no issues on a driver. crazyL

Re: '72 C-10 3-Speed to 4-Speed Swap?
 

Appreciate the reply.

I just found out that this trans is from a mid-70's Monza. I did a little research in the meantme and someone mentioned it may use the larger driveshaft yoke, something like the TH400 trans yoke. Is that correct? And would there be any other issues being from a Monza?

Re: '72 C-10 3-Speed to 4-Speed Swap?
 

No, same yolk as your 3spd. You might replace the front bearing before you run it(as a precaution), that is something I do whenever I have the gearbox out. I bet you will like the ratios, its a bit of a stretch from 3rd to 4th, but the rest get you rolling quick ,with a 3.42 or 3.73 gear......crazyL

Re: '72 C-10 3-Speed to 4-Speed Swap?
 

Glad to hear the yokes are the same. I'd be looking forward to the lower 1st. The 2.85 now is a little rough at times.

Bill