The Stovebolt Site Forums The Shop Area Engine Shop Anyone running a 3 groove saginaw?

I just picked up a really nice Saginaw 4 speed. It has been rebuilt or was not in a vehicle very long. The case is perfectly clean.

It is a wide ratio 3 groove unit, 3.50, 2.48, 1.65, 1.00 ?

I think I'll replace my SM420 with it, it should work well with a 3.07 rearend. The 420 is 7.05, 3.57, 1.70, 1.00

Who has one of these, and what shifter are you using? What should I watch out for? It will bolt right into a 261 bellhousing, right?

I don't have the three groove version, but the same shifter will work. I used the one sold by Patrick's and it works great. It is a Hurst shifter with some small mounting modifications made by Patricks to mount it up near where the reverse light switch is mounted (the switch has to be removed and replaced with a plug of some sort.

The biggest issue I had with the modification is with the brakes. If you convert to a dual master setup the shifter does not give you much room (about an inch) for the brake lines coming out of the master. It is a tight fit, but it can be made to work.

Hope this helps. Good Luck.

I have one in a 63 Nova. I use a Hurst shifter on it. I've never had any trouble with it, but I treat it like it was made of glass. No speed shifts, no killer downshifts. So far, so good. (3 years in the car.)

Josh, I had a 3.50 first gear 4spd Saginaw in Joy's 51 truck when I built it 7 years ago. Low gear was too low for my tastes with a 235 and 3.40 rear end gears.It should be ok with a 2.73 or 3.08 rear gear. I still have the tranny collecting dust in my barn.I then installed a 2.85 first gear 3 spd Saginaw,slightly doggy on take off but pulling the 1400 lbs travel trailer was no problem at all.With the 261 in the truck now , the 4 spd OD A883 trans and the same 3.40 rear, it ok with the 3.09 first gear.
Bolts right up to a 48 and leater truck clutch housing, 21 inches long like all GM car trannys. I use swap meet Hurst shifters, modify the mounting bracket to move the shifter as close as possible to the main case, cut and weld the shifter rods to fit.Then make up a shift handle, bend it suit the situation. Speedo driven gears are easy to get from the various Camaro after market sites.
Pull the tranny apart, generally the spring washer on the mainshaft between first gear and the rear bearing is flattened,resulting in too much main shaft play.The shaft walks back and forth beating up on the bearings.I throw the feeble spring washer away and shim the gear using king pin shims or what ever.The input bearing is also usually worn, you can buy the bearings cheaper at a bearing distributer than the rip off prices on some websites and auto parts stores.Las Vegas Driveline is a good source of reasonably priced syncros if ya need them.
Some say they break easily,GM used them behind 300 hp or less. I know guys with built small blocks abusing Saginaws with no problems.

I did up a spreadsheet to figure out gear ratios versus speed, and it looks like it will work very well. 1st gear on the Saginaw with a 3.07 falls slightly higher than 2nd gear on the SM420 with a 4.11, which is what I always start out in right now and it is a bit low.

I should be able to stay in the powerband of the 261 all the time, too, with I probably couldn't do with the SM420.

This is the nicest used transmission I have ever seen, and there is no noticable wear anywhere, and the seal on the output yoke looks new. The input shaft bearing feels really good. The shift levers pop right into and out of gear like butter, and the detents all have about the same amount of feel. I'm going to pull the cover and check out the innards before I use it.

I'll probably order a new Hurst shifter from Jeg's and fab a bracket and levers. I am really picky about shifter feel.

Where does the shifter come out in a AD truck if you mount it right where the main housing and tailhousing meet?

Thanks for the heads up about the master cylinder, that was something I was planning on doing.

Anyone got any pictures of the shifter installed?

Go with the shifter from patricks,Its a hurst with all the mods done already, with a nice stock looking shifter handle at a good price. as far as the duel master cyl you need to buy two close right angle bends,you will clear the shifter linkage by about 3/4 of an inch.good luck. old navy 51...................

Here's a photo of the shifter in my wife's 51 Chevy.Although it's a A883 OD tranny now, the shift lever is in the exact place as the Saginaw lever.The location left to right is between the gas pedal and starter pedal and 9-1/2 inches foward of the seat base.Take a piece of broom stick and place it there to get an idea of the feel, you're a big guy right? You may have to bend the stick over to the right some for leg clearance. It's fine for me, 6 foot 165 lbs.
Hurst shifters never really wear out,a 20 buck swap meet Competition plus model generally only needs a clean up to feel as good as new. But if you don't have a welder and so forth, a new one from Patrick's with the proper mounting bracket and shift levers might be a better bet.
[img]http://img.villagephotos.com/p/2003-1/95040/FMICQ-Mvc-022s.jpg[/img]

I'm getting a red X, Tony.

I would like the shifter to be mounted as close to the middle of the floor as possible. I hit my knee on the SM420 shifter when it is in reverse.