The Stovebolt Site Forums The Shop Area Driveline Any difference between L6 and V8 bellhousings?

Hello, I have a ‘62 C10 with a ‘57 235 L6. It has a SM420 4 speed transmission now. I have a line on a ‘62 Saginaw 3 speed with overdrive which came from a SBC.

Checked the archives and did not see a thread similar to my question.

Any difference in bell housings?
Can I use my current housing?
Need to buy V8 housing?

Need to switch over as I live pretty rural, and 55 mph is tough on the old girl.

Thanks in advance,

Hy Beartooth-Cowboy, from what you have told us the three speed should swap into place of the four speed with no problem, the driveshaft length will probably be different, hope that helps.

The bellhousing, clutch, etc. will be a direct bolt-in swap. You'll need to come up with the electrical system to make the OD operate properly and a shifter of some type, since the Saginaw was intended to be used with a column shift. Hurst used to make a floor shift conversion for that transmission, but you'll probably end up with some problems with shift rod clearance around the OD unit. BTW, a Saginaw with OD is a VERY scarce item and most people who know what they have will be asking an outrageous price. Another, less expensive approach would be to use a T-5 OD 5 speed in place of the SM-420. It's a weak sister compared to the 420, but it will give you better road speed. You'll lose most of the load-hauling capability of the truck, however.
Jerry

Thanks for the fast replies.

I think I got a pretty good deal on the Saginaw with OD; much cheaper than a T-5 once you consider everything involved : spacer/adapter, clutch ...

Thanks again,

BC

The Saganaw overdrive transmission was not available until 1966. It can be identified by the 7 bolt side cover. They are very sought after as they are full syncro units. A 62 transmission is a SM319 Muncie with an R10 BW overdrive unit. It can be identified by the 4 bolt side cover. 1st gear is non syncro in the SM319. They work well in most applications.
Fred

Your original question was about the differences between the bellhousings. I had a problem trying to use an older L6 bellhousing for my V8-T5 swap. The starter area was different and my newer (70s) starter wouldn't fit into it. I had to find a "621" bellhousing. Sounds like you should be fine though.

Thanks again for the helpful advice and answers. This is a great community of like-minded enthusiasts.

The bell housings will not enterchange but the trans. will fit either one.
George

I have a few cast iron bells from the 1963-1972 era. The bell will bolt directly to a SBC or an L6 from 1963 up to maybe the mid to late 80's. I just don't know when GM changed to a newer bolt pattern. Some bells have a center bore of 4 + 11/16". The others have a center bore of 5.125" IIRC. Your 1962 bell should have a hydraulic PS clutch fork and should have a 4 + 11/16" center bore. You should measure the diameter of the front bearing retainer just to be sure it's the same size as the bell bore. The input shaft should be 10 spline and the correct length.

Thanks Lugnutz and Wrenchbender. Good information. This project is in its infancy, but I have been getting good advice here.