Thread: 4 speed strength

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Does anyone know how much torque a stock 4 speed GM tran's can take. I am putting a big block in my truck and I have herd they can bust the main shaft. This will be a built engine not stock and I do tend to be hard on it. Is there any manual tran's that can hold up to high abuse and torge that is still able to be used on the street.
Thanx

i was going to put a four speed behind my built small block, but decided against it because i already had a th350. I'm not sure of the exact numbers but it really depends on what four speed you chose, from what i gather there are three main coices, saginaw, muncie and borg warner. I'm pretty sure saginaws arent that strong. Muncies and Borg warners should be able to handle the abuse.

Well chevy trusted the M22 rock crusher to do the job behind the big boys, ie LS7, L88, ZL1, 500 + hp/tor depending on tune.

Leave the M21 & M20 to the mice motors and the saginaw to the 6 bangers.

in a truck i can not see useing any gm 4 speed they are all junk the truck is heavy and i do not think it will hold up. a ford top loader or mopar is what i would look for. the 22 was a ok trans but try to fine a good use one is tuff .a lot of the gms 4 speed trans have been beat to death so theres a lot of junk out there

muncies are ok just build em up
right

What about the richmond gear, T10 4spds that they sell in summit and a few other places

hi hp and torque in a heavy truck a aluminum case trans is not what i would call idea.m22 or m21 is not up to it. if this make more hp and torque and in a heavy truck it will brake the case is to lite and the in put is to small and the cluster pin is to small ok for a lite car but .a truck this is not the trans

If it's a mud bogger or 4wd truck, why not a Muncie SM420 4spd with low 1st, shouldn't be too hard to find 1. They put them in '60-'67 Chevy and GMC 4X4 trucks, deffinetly 3/4 ton, maby 1/2 tons. The trucks that had them had 4.56 gears. They have a PTO that comes out of the passanger side. They used variences of this trans up into the early '80's, in which some of the trucks had stock 454's.

I agree with Pat. For heavy duty use a Ford top loader or Mopar 4 Speed. If this is any indication of what the serious racers use, Lakewood makes Chevy bellhousings with a Ford or Mopar bolt pattern so you can use one of those transmissions behind a Chevy. I have run a Muncie behind 2 425+ hp 427s. One in a 4000 pound Biscayne and the other in a 3500 pound Chevelle. They both survived in a street/strip car, but I was not running them flat out in serious competition. I was using what was in the cars, if you are going to go shopping for a transmission, might was well get one that will last a long time. If it meets your needs, you might also consider a Nash 5 speed.

my $.02

Pat

Here's another option with straight-cut or helical gears depending on how much noise you can tolerate......
http://www.g-forcetransmissions.com/tran_gt-5.asp

I looked at the richmonds but thought they would be to week. That G-force looks great but I am thinking my motor will produce more than 500 ftlb's. I have heared of a Jerico I think. Anybody use those.

toploader....
http://www.4speedtoploaders.com/
jerico....
http://www.jericoperformance.com/
tremec TKO....
http://www.brothersperformance.com/s...re2600708.html
upgraded M22....
http://www.carcraft.com/howto/56399/
http://www.autogear.net/

How about the Super T-10?

Maybe this is the answer, 650 ft. lbs. of torque capacity.....
http://www.ddperformance.com/GM%20T56.htm

www.m-22.com about 750 ft lbs of torque scroll down the page he has a few differnt trannys including one with OD........scooter