Technical 4-Spd. Tranny

Which 4-spd. tranny would you go with? Inline 235 chevy 6. The car presently has 2 Carter Webers on it with a 3:70 rear. The car is set up to look like a period correct H/Gasser.....Thanks JT

 

Muncie or Saginaw will bolt up with stock parts. Both are original equipment in GM's.


jerry

 

^ x2

 

Saginaws are cheaper, will definitely hold up to a 235, and are available with steeper low gear ratios to give your six more dig off the line.

 

Put 5 speed out of a S10 pickup in it. It will hold anything the 6 has to offer and you'll have the OD.

 

For the cost of a rebuildable Muncie you might be able to make up 2 or 3 Saginaw crash boxes. The old trick used to be to grind off every other tooth on the syncros and it actually works pretty good once you get the hang of it. Don't forget or discount the Super T-10, also GM OEM equipment. The BW Super T-10s have quite a selection of 1st gear ratios, from lower standard ratios like 2.42 to radical 1sts like 3.10. There's a chart online somewhere (maybe in somewhere in here) that shows the ratios and how to identify them by the rings on the input shaft. I.E., the 2 rings on my T-10 indicate the 2.42 1st gear. Disclaimer: My numbers may be off a digit or 2 but the info is valid.

Saginaws can be had sometimes for $100 in working condition, most Muncies start at $500 for a fixer-upper and also seem to always have a bolt boss welded back on. Saginaws and some GM Super T-10s are cast iron cased, all Muncies and later ST-10s are aluminum cased, the ST-10 aluminum case is superior in strength to the Muncie. These are things I've picked up over the last several years while gathering parts. I hope at least most of it is still right.

 

what period? If it's from when folks were actually racing stovebolts, then a 4 speed was just a pipe dream...you'd be running a 3 speed, and there would not be a sychro on low gear.

 

And you might only need to be running 1st and 2nd at the drags with the 3.70. It will buzz to 6500-7000 with solid lifters.

 

6500 7000 maybe once

 

Most rebuilders get about 850 for a completely rebuilt Muncie, more for an M22....a Saginaw would likely be perfect for your set up, run a Hurst in order to have a nice shifter feel...maybe find a good used Saginaw with shifter etc for a couple hundred.

 

I have a very nice Super T-10 close ratio if interested.

 

You will want a steeper first gear than most Muncie transmissions have,you may want at least a 2.9 first gear,probably in the 3.0s.Most three speeds had low first gears,you put a 2.20 or so first gear in there and it will be a real dog off the line.You also will want a heavy flywheel to help get that six moving unless you have a light car. ROY.

 

Saginaw four speeds were available with low gear ratios of 2.52, 2.85, 3.11 and 3.50.

 

Back in the day, I put a Saginaw behind a 235 after reading an article by Tex Smith. (Hot Rod Mecanix?) Per the article I found a Monza 4 speed with 2 grooves around the input shaft. That is how the first gear ratio is identified. Don't remember the ratio though. It worked great.

 

Hey, guys, from somewhere on the Inliners Int'l site, Saginaw 4 speed ratios & input shaft groove codes.

0 Grooves - 1st/2.85, 2nd/2.02, 3rd/1.35, 4th/1.00
1 Groove - 1st/2.54, 2nd/1.80, 3rd/1.30, 4th/1.00
2 Grooves - 1st/3.11, 2nd/2.20, 3rd/1.47, 4th/1.00
3 Grooves - 1st/3.50, 2nd/2.48, 3rd/1.66, 4th/1.00


Later, Kinky6

 

Here's another vote for the Saginaw. You can find it cheaper than the other 4 speeds, it can handle anything the 6 can put out, and it bolts up. The ones with the lowest first gear ratio are normally found in 4 cylinder Vegas. The Vega 4 banger needed all the help it could get to get the car moving, hence the lower gearing. As an added bonus, the Vega 4 never developed enough power to hurt the transmission. It is a far more rugged trans than the Vega really needed. A lot of the earlier Vegas had an Opel transmission that is easy to recognize because it has an integral bellhousing, while the Saginaw has a separate bell and bolts up the same as other Chevy 3 and 4 speed manual transmissions. I think the Opel trans was only used one or two years, most stick shift Vegas had Saginaws. Easy way to tell if you find a Vega in the junkyard, if it has the Opel trans it will have a very skinny shift lever, about 1/2" diamenter, while the shift lever for the Saginaw trans is very beefy.

Back when Vegas were a dime a dozen in the junkyard, the Sag 4 speeds were a popular swap in Chevy/GMC pickups because of the low first gear ratio.

 

Thanks for all the replys. I'm going with a Saginaw w/Hurst shifter.

 

JT, do you have a Saginaw trans already?

If not, try to find the 3.11 gear unit first, with the 2.85 as second pick. The 3.11 gear w/ your 3.70 rear axle, will give you an effective 11.5:1 ratio, which will get you moving pretty good. The 2.85 would yield 10.5:1, which is still not bad.

With the 2.54, it might feel a bit boggy on the revs, while with the 3.50 you'll only stay in it long enough to stomp on the clutch again.

Later, Kinky6

 

for a 6 banagar..a saggy.

 

get the strongest trans you can find & afford , you never know when the 6 might let go & if you find a healthy v8 you've already got the trans set up & ready to go

 

Sag is a direct bolt-in. We did a cpl of tri-5 Chev 6's for customers, same driveline and all.

4TTRUK

 

And a dam good lookin one for sure
JT let me know if you are still looking might have one.