I remember reading an article on the subject long ago.....has any one else read or have any info on the subject
the article was something about adapting the Saginaw planetary over drive unit to the Muncie trans....if i remember correctly some guy in Florida was doing these
I bought a new one. Stronger than Muncie, no guess work. M21Y http://www.autogear.net/orderform/4speedpricing.htm
They do, but there are companies out now that make complete gear set's to allow an overdrive in the stock box.. Basically it turn's the trans into a 3 speed with od but retains the look of the typical 4 speed.
I put one of these in my 66 Corvette and it's worked out well. I bought mine from the gentleman in Florida. His web site is www.M-22.com Lots of good info on there.
I haven't run it yet! It has a little less OD than a 700R4, so it should be similar cruise. I have 3.50s in a ford 9". It should turn about 2200 at 70 mph.
Early C4 Corvettes came with an OD unit behind their 4 speeds. The one I worked on was an '84, I don't know how long they used them.
Yeah, the famous (or should I say infamous) "4+3". Unless you're into constanly dicking with your transmission, best forget about that one.
I bought a kit from D&L transmission http://www.dandltransmission.com/ and modified a muncie tranny I had. I have it in my GTO and it works great on the highway.
I did this a couple of years ago can't find the invoice but I think the gear set was about $450 the OH kit $150. The parts are made by auto gear equipment. The gear set has the cluster, 2nd gear to balance the split and 3rd gear for the OD. The new ratios are 2.20, 1.51, 1.00, .859. Makes a 4.11 rear act like a 3.55. I did it because I wanted the OE look. Looks and works geat only use 4th on the highway
I'm hanging on to a saginaw 4 spd just for the purpose of adding the 3 spd OD to it when I can find one. I'll just keep scrounging the swaps till i do.
I'm building a Gasser ....so I'd be doing it for the same reason...Muncie look vs a tremec look..... oh and Lobucrod...I have one of those Saginaw 3spd O/D.....how much insulation can i get for one of these??
Wasn't there a Muncie M-15 that was put into Chevy pickups in the early 80's? Some also used a New Process 4 speed of the same arrangement. Both were overdrives, looked like M-21. They weren't very common, shifters also hard to find unless reconfiguring can be done. That's why I'm gonna try to use a 97 4.3 S-10 5 speed in my car. I know it doesn't have the good old muscle car 4 speed look, but it has overdrive. I've driven a couple of customer's vehicles, and thinking low gear might be too low.
I used one of the New Process 4 speed o/d trans in my 62 Chev truck for years. Worked really well. It's still laying under the bench waiting for a new home.
September '08 Hot Rod Deluxe has a feature on factory stick overdrives, and they cover the "Mopar in a Chevy".
for what I understand that tranny is good for a flatty or very small V8....but not much good if you planning of putting real power in front of it
I wouldn't advise going drag racing with the M-15. If you're looking at real power, time to cough up for a Gear Vendors or a modified Viper T-56.
to get around the 488 gears in his gasser, my dad went with a newer 6 sp... can start in 2nd if you want
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