| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,130 Posts1,056,717 Members48,454 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Oct 2009 Posts: 426 Shop Shark | | Shop Shark Joined: Oct 2009 Posts: 426 | Does anybody know how good of a build can be done to the saginaw 3speed tranny? Im puting a 396 in my 63 in the spring and want to keep the coloumn shift. How much hp and torque will this tranny take? Would I be better with a hd 3speed | | | | | Joined: Oct 2003 Posts: 5,152 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Oct 2003 Posts: 5,152 | How are you going to drive it? How are you going to load it?
If used gently it may last a long time. If abused the HD 3-speed won't last either.
1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble... | | | | | Joined: Oct 2009 Posts: 426 Shop Shark | | Shop Shark Joined: Oct 2009 Posts: 426 | Just an everyday driver. I plan to build around 350-375hp engine running on pump gas. This will not be a race truck. Just want to be sure that I'm not going to rip the tranny out w/normal driving | | | | | Joined: Oct 2003 Posts: 5,152 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Oct 2003 Posts: 5,152 | There are people running the Saginaw 4-speed behind 454's successfully, and since that 3-speed is basically the same design I'd expect normal driving would be fine.
Pulling a heavy trailer or drag racing would change my opinion and possibly your experience.
1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble... | | | | | Joined: Jan 2008 Posts: 69 Wrench Fetcher | | Wrench Fetcher Joined: Jan 2008 Posts: 69 | Are you sure you have a Saginaw? If first gear is not synchronized, then you probably have the Muncie SM318, although it is often referred to as a Saginaw. It's the most common transmission they used in the 6cyl cars and 1/2 ton trucks back then. It was available in the trucks until around 1967. As OldSub said it may last for years if driven easy, but they don't like abuse. I had a mild 327 in my first '65 pickup as a kid, and I busted several of them. But of course I was asking for it. Best of luck.
TruckNut
Be kind, courteous, cheerful and helpful - And someone will take advantage of you.
"Quiting smoking is easy, I've done it hundreds of times." Mark Twain
| | | | | Joined: Oct 2009 Posts: 426 Shop Shark | | Shop Shark Joined: Oct 2009 Posts: 426 | 1st gear is not synchronized so its probably the muncie. I have the casting numbers somewhere. Would the saginaw be a better choice of trans? I want to retain the coloumn shift. I have the 12bolt truck reared w/3:73 gears | | | | | Joined: May 2006 Posts: 8,351 'Bolter | | 'Bolter Joined: May 2006 Posts: 8,351 | Here's a little food for thought, the SM318 was used behind 396s and even 427s as the standard equipment transmission in passenger cars. It also saw use behind Feullie 283s, Power-Pak 2x4bbl 283s, Feullie 327s, 348s, and even the 409. Driven normally, and not abused, it should be fine.
Bill Burmeister
| | | | | Joined: Jan 2008 Posts: 4,962 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,962 | If your synchro gear and shift forks aren't worn like a lot of them are, with todays lubricants it should last a long time. | | |
|
|
| |
