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Anyone with experience on a saginaw 4spd swap into a lwb truck? I pulled an sm420 out and rebuilt and installed the 4spd. Now I need to modify the foward driveshaft but once its done all that'll stop the front shaft from walking fore & aft will be the hangar bearing. A one piece probably won't work because my 62 frame is an "X" with a small tunnel in the middle and could rub the shaft at the suspension limits. Like to hear from more of you on a single 2bbl weber for a 261 too. Thanks

I don't know the differences between your '62 and a '66 or '75, but my '66 came with a powerglide and my '75 came with a turbo 350. Both use the same type of yoke as the saginaw and I believe are also the same length. I'd look for the front driveshaft section from an automatic or 3-speed truck, expecting that it would be correct for your saginaw.

I've not had my '72 that far apart, so I don't know but would expect it to be the same.

This is all just a guess....

Thanks for the reply. I already have the slip yoke for the transmission. I think after 62 chevy went to a ladder type frame which would eliminate the chances of a 1 piece shaft hitting anything. and thats my problem w/ a 1 piece on a 62. Modifying the front shaft that I already have is the other. Is it O.K. for it to have a slip feature at both ends with only the hangar bearing holding it?

I don't know, but I don't think it would be a good idea. I think on the later trucks with two piece drivelines the front piece extended through the hanger and was held in place by the bearing in the hanger.

Been years since I've had one of those apart.

Old Sub, the foward driveshaft IS held/supported in place at its rear end by the hangar bearing. Do you still think thats a bad idea?

Maybe I don't quite have the picture...

What I believe you started with is a slip joint in front of the bearing and a solid connection to the SM420.

If you use a slip yoke in your saginaw and keep the existing front shaft you will have two slip joints and could have problems as a result. But maybe not... It would be a problem if the shaft could get too short and fall out, or perhaps just wobble.

As long as the fully compressed length isn't too long, its never going to be too long. But I'd worry that it could be too short.

I'd look for a front shaft that does not have the slip joint from a truck with a 3-speed or an automatic.

Old Sub, thanks for hanging in there. Indeed my sm420 has a clevis w/ the ujoint right at the back of the transmission. But the male spline on the other end of the shaft is after the hangar bearing. Then the rear shaft splips on it and ujoints to the rear end.

Okay, I misunderstood what your current driveshaft looks like. Most of what I've been worried about should not be a problem. What you describe is basically what I remember having on later trucks.

The question at this point is only how do you connect the driveshaft to the transmission, and the answer is either to modify the existing front shaft, or to locate one from a truck that had a 3-speed or an automatic. Automatic is the surest bet, and I'm pretty sure a Powerglide and Turbo 350 are the same length as the Saginaw 4-speed, so that should be an easy fix.

Old Sub, Thanks for your advice. I'll be trying to locate a shaft I won't need to modify right away.

You're welcome. Tell us how it works out!