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best gm 4speed

Discussion in 'The Hokey Ass Message Board' started by jetmek, Sep 25, 2007.

  1. jetmek
    Joined: Jan 12, 2006
    Posts: 1,847

    jetmek
    Member

    the recent post about the t-10 has me wondering. i 'd like to ditch the t350 behind my blown sbc but dont know which is best. muncie or b-w t10? what ratio should i be looking for to run with a 3.50 rear in a deuce sedan? i know id have to change the d/s yoke for the b-w but what about the muncie? is 500$ too much for a muncie?
     
  2. squirrel
    Joined: Sep 23, 2004
    Posts: 43,702

    squirrel
    Member

    probably ought to go with either a Super T10 or a M22. M22 will cost a fortune.

    Both use the 26 spline clutch and the big driveshaft yoke.
     
  3. arkiehotrods
    Joined: Mar 9, 2006
    Posts: 5,484

    arkiehotrods
    ALLIANCE MEMBER

    T350, powerglide, and Muncie have same spline, so you wouldn't have to change the yoke. I replaced the factory 3 speed in my Nomad with a M-21 Muncie, and it bolted right in, same driveshaft, yoke, etc.

    The M-20 is the wide ratio box, with a lower first gear. M-21 & M-22 are same ratio, M-22 is stronger (and pricier). I think a wide ratio M-20 with 3.50 rear gears would give you good off-the-line acceleration.

    $500 is not too much for a Muncie if it's in usable shape. I paid $800 for my Muncie (with Hurst Competition Plus shifter) in 2000.
     
  4. jetmek
    Joined: Jan 12, 2006
    Posts: 1,847

    jetmek
    Member

    ok ill kick myself now for passing on a s-t10 with 6 rings this weekend for 450 smackers. guess i shouldnt be so cheap next time i find one
     
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  5. jetmek
    Joined: Jan 12, 2006
    Posts: 1,847

    jetmek
    Member

    thanks...appreciate the input. a buddy has a muncie for sale, ill have to ck what model
     
  6. I have a M-21 close ratio box that I'm happy with..
     
  7. HemiDave
    Joined: Aug 7, 2006
    Posts: 463

    HemiDave
    Member
    from Austin, TX

    If you are in that price range, consider a 5 speed....just sayin'....

    Dave
     
  8. jetmek
    Joined: Jan 12, 2006
    Posts: 1,847

    jetmek
    Member

    ive been led to believe t-5's are pretty weak....friends have had them come apart behind flatheads and stock 305's
     
  9. HemiDave
    Joined: Aug 7, 2006
    Posts: 463

    HemiDave
    Member
    from Austin, TX

    Depends which one you get. One that came out of a V6 car..yeah, it's gonna be weak. they make 'em to handle 600 HP and all ranges in between. Finding one out of a Z28 or Trans Am or 5.0 Stang should get you a stout unit.

    Dave
     
  10. jetmek
    Joined: Jan 12, 2006
    Posts: 1,847

    jetmek
    Member

    thanks for the advice. do you know it they are a bolt in or will it require moving the rear mount and driveshaft work?
     
  11. 392_hemi
    Joined: Jun 16, 2004
    Posts: 1,737

    392_hemi
    Member

    Muncie is a bunch stronger than T-10. Not sure about the new Super T-10s from Richmond though. Had a M-22 in my '70 Nova SS. Out of all the cars I've owned, that one was the most fun to drive, and fast as hell.
     
  12. HemiDave
    Joined: Aug 7, 2006
    Posts: 463

    HemiDave
    Member
    from Austin, TX

    Probably some shifting of mounts since they are pretty long but they make adapters for many applications these days. The OD really comes in handy to reduce cruising rpm and gas mileage....increasingly important these days...

    Dave
     
  13. squirrel
    Joined: Sep 23, 2004
    Posts: 43,702

    squirrel
    Member

    I wouldn't put a T5 behind a blown motor....maybe I'm just chicken after seeing what blown big block can do to a th400? besides you won't need all them gears, just run a mild rear gear (3.00-3.50) and you'll blow away the tires in first anyways with a 2.21 first gear 4 speed. 3.00 gears are decent on the highway, if that's in your plans.
     
  14. Squirrel is right, reading between the lines I feel your motor is more of a torque monster, And in that case you won't need an overdrive if you have a 3-owe gear, wouldn't matter if you did use a 3.50 with a 5-speed, the first couple gears are pretty much useless any way, and the 4-speed is strong with-out spending cubic dollars.

    Am I wrong?
     
  15. twofosho
    Joined: Nov 10, 2005
    Posts: 1,153

    twofosho
    Member

    Squirrel said it first, GM spec T10 and M20 (2.54 or 2.56 low)-M21 (2.20 low) Muncies use the GM 10 spline input shaft (main drive gear in GM parlance). They also accept the same driveline yoke as powerglides, T350s, and T200R4s (the Muncie short tailshaft versions can also utilize the same length driveline as these automatics). Super T10s and M22 Muncies use the 26 spline input and a T400 yoke.

    All for as strength, T10s aren't much different from most V8 T5s, and probably aren't as strong as the later Ford world class variants. M20 and M21 Muncies are a little stronger. M22 Muncies with their coarse cut gears quite a bit more, but you're stuck with a 2.20 low gearset (I've read the 2.20 low gearsets were originally intended for road racing corvettes) and need to be paired with a stiff rearend gear when used for digging out (3.90s or steeper with 4.11 and 4.56 not uncommon). Super T10 was used in GM cars after they stopped using the Muncie and are commonly thought to be as strong or stronger.

    Of all the factory offered 4 speeds, the 18 spline Mopar (think HEMI, but also used behind 440 six packs) had the reputation of being the strongest with it's 23 spline brethren not too far behind. The Ford top loader falls somewhere in the middle (on a par with the 23 spline Mopar probably). The 23 spline Mopar 4 speed is the only one factory adapted to an overdrive configuration, essentially becoming a 3 speed+ overdrive and loosing the main reason for four gears (minimizing gear spread). It also seems a great many came with aluminum cases containing an unbushed countergear (the same arrangement as all stock aluminum case Muncies as a matter of fact), and are considered by most Mopar people as a weak transmission.

    Depending on what you're doing and how much power you actually intend to get to the pavement, anyone of the above could be your answer, but don't think it's going to be a cheap answer unless you've already got a good one laying around because rebuilding any one of them has gotten quite expensive. Remember too, in the 70s when the tires got a lot better and a lot of cars started dropping into single digit quarter mile ETs, multi stage Lenco planetary racing transmissions would often be found in place of anybody's factory 4 speed, and were likely selected as much for the reliability as for the automatic like shift consistency.

    A modern high torque capacity 5 or 6 speed might actually end up more cost effective in the long run (or short depending on your driving style).
     
  16. tomslik
    Joined: Mar 3, 2001
    Posts: 2,162

    tomslik
    Member



    yeah tight-ass, i just gave 550 for one just like it.
    little deeper 1st gear than what i wanted(oh well, just have to run more tire)....


    oh yeah, i owe squirrel an apology.
    he was right and i was wrong about m20's ans m-21's.
    relying on my memory again:(
     
  17. jetmek
    Joined: Jan 12, 2006
    Posts: 1,847

    jetmek
    Member

    ha ha thats me:D you wouldnt know it to hear the wife bitch when the mastercard bill comes tho!
     

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