Muncie 4 Speed In A Truck?

[jjester6000]

So I'm getting the engine put back together on 'Ol Yeller, and I was thinking "Would a Muncie 4 speed be a good option for a truck?"

These trucks never came with them, but it's got to be tougher than the saginaw 3 speed already in there, right?

At one point a few years back, I did briefly have a Saginaw 4 speed installed in place of the 3 speed, and it didn't last long at all (My burnout attempt may have something to do with shattering reverse). Would a Muncie fair better?

 

[Ricko1966]

All Muncie 4 speeds are not the same. Personally I'd look for an np833. But if you go Muncie before you install it,look real hard,the counter shaft actually goes through the transmission case the only thing sealing it is the.interference fit between the shaft and the case,make sure the one you buy is not wallered out there. There is a patch,it's not right but it will stop the leak. Cut a copper gasket to cover the end of the transmission,sandwich it between the bell housing and the transmission.

 

[pduffyd]

There is always a sm465, or, an nv4500 conversion.

https://high-impact.net/nv4500-conversion-package-for-chevy-truck-with-sm465

 

[Donald]

Stay away from Muncie's made in 63 they had no bushing under the 1st gear and can seize to the out put shaft under heave loads .

 

[JT58]

I have the SM 465 in mine. It's the 4 speed with the granny low but seems like a rugged trans, has a cast iron case. Great for crawling off road, too.

 

[DoubleDingo]

You have 3.55 gears, a 4 speed will not have a good 1st gear ratio. If I were you I'd be looking for an sm420 or sm465. In Mean Green I ran 3.54s with an sm420, fun to drive, and good street manners with the 3.54 gears

 

[MikeB]

There were 3 versions of the Saginaw 3-speed. The one with the lowest 1st gear (higher numerically) was sued in the smaller 6-cyl engines and couldn't handle very much torque. A version with 2.54 1st (less torque multiplication) gear was used with 305 and 350 trucks. As for Saginaw 4-speeds, they couldn't handle the torque of small blocks much beyond a base 327 or base 350.

If you are talking about a Muncie 4-speed like those used in cars, the M20 with 2.52 or 2.56 1st gears were designed to handle the torque of at least a 327 V8 and on up to 350s. The M21 with 2.20 1st gear could handle even more, and the M22 "rock crushers" (also with 2.20 1st gear) were used behind the high performance 350s and even big blocks.

 

[Fat 454]

for truck boxes an SM465 is a better bet then the SM 420 - have a detailed read on the those and the NV4500 on the "Novak" transmission conversion site. They have really good info there. Also a couple of really good rebuild videos used to be available on U tube if you search under SM465. We have a factory sm465 behind a 454 in our dually - its a truck box with truck performance, but bullet proof.
Had a muscle car M21 4 speed behind a big block in a 2wd blazer also - "street" truck only ( no towing ) but that was a wailer. Get the HP book on muncie 4 speeds by "the guru" Paul Cangiolosi to learn all about those.

 

[Fat 454]

Also, when you do the conversion - post it here, with before and after thoughts ...

 

[Fat 454]

And lemme know if you wanna trade on the '74 GMC grille - thats cool !!..

 

[Craig Nedrow]

Muncie in this 283, 283hp clone.

 

[Copymutt]

Ive run & rebuilt both M-21 & M20 in my 55. For the close ratio you need 4:11 RE or big block torque to get started in a hill.

 

[Craig Nedrow]

I prefer the wide ratio, as the first gear is fairly low, and helps you get going. Like Jim said, a closes ratio in a lower torque motor is ok if the car is light, a truck not so much. Personally, I grew up with the Muncie, and the Hurst Completion Plus shifter, used to modify the shifter for short throw. Some say the top loader is stronger, and it may be, but the Muncie shifts way faster then the top loader. Pop the clutch in first gear, keep pressure on the shifter for the next gear, side step the clutch, and instant shift, so much fun. That black 53 chevy had 4:56 posi, engine would turn 8500-9000 rpm's, (forged internals, and Jahns forged pistons 12.5:1,) sounded heavenly. Still not a BBlock, they are a whole different setup.