The Stovebolt Site Forums The Shop Area Driveline Saginaw 4-Speed?

I'm looking into a Saginaw 4-Speed to replace my original 3-Speed in my '72 C-10. This Saginaw is supposed to have a 3.50 1st, which I really like as my 3-Speed has only a 2.85 1st. I put extra tall tires on the back to raise up the 3.73 Rears, so the 3.50 1st will work a lot better, plus give me an extra gear. I'm more familiar with Muncie's but I trying to verify if this will be a direct swap, using the same driveshaft and all.

Any info would be appreciated.

Bill

They should be the same length. The splines on the input may be different than the ones on your transmission.You would just need to change the clutch disc.

If your comparing a Muncie car transmission to the Saginaw they are the same length. I've swapped them back and forth. The Saginaw's were cheap years ago and when I broke my Muncie I put in a Saginaw while I saved up my $$ to fix the Muncie. Most Muncie's had either a 2:20 low gear or a 2;54 low gear. I know back in the day when we went junkyarding we would look for Chevy Vega's and grab a Saginaw out of them. The only caution I can offer is they don't take much abuse. My Chevelle would eat one up in a couple weekends if I was out running the boulevards much. Don

"I'm looking into a Saginaw 4-Speed to replace my original 3-Speed in my '72 C-10."

Bill, there is a very long established manual transmission parts and rebuilding facility in Los Angeles called Al Silk Gear Company. I was in there once on another matter and they showed me something about the Saginaw 4-speed that you might want to consider. The Saginaw 3-speed was converted to a 4-speed by making all of the gears very narrow and keeping all 4 forward gears and reverse in the main case that is the same size as the 3-speed case. Narrowing the gears reduced their load carrying ability.

In contrast, the Muncie has wide forward gears in the main case and reverse is in the tailhousing.

I have a '78 El Camino with a factory 350 cid engine and Saginaw 4-speed and there have been no transmission problems because I drive it like the old man that I am (66 years). The only maintenance I've had to do on it is fix oil leaks by replacing the tailhousing bushing and oil seal, the front seal and the shift shaft O-rings.

The Saginaw is a good transmission for light-duty to moderate use. I worked with a man who had been in the engineering department at saginaw when thiose transmissions were developed- - - -for use behind the 4-cylinder Vega engine! They beefed up a few of them with special heat-treat procedures and some heavy duty needle bearings to run behind a drag-racing 350 one of the engineers campaigned, but he said it was still a challenge to keep one together for long under racing conditions.
Jerry

Appreciate the info y'all.

Bill