Hi, am wondering about the feasibility of swapping the Muncie out for one of
the side loaders from an early eighties Chevy truck. I think GM calls it the
NP260 (MY6) which I guess is like the old New Process A833, which is really
a 3 speed with Overdrive. The ratios are :3.090 1.670 1.000 0.730 It's
basically a stock engine, so with 180 HP am not too concerned about tearing
it up. The looks and runs great, but the truth be told, my wife and daughter
are the only ones that drive it. If it got better mileage and it was an
easy swap, I might go visit the wrecker. So if you can clue me in on
splines, yolks, tail shafts and shifter placement,ect, I'd be much obliged,
There is one other transmission to consider. The T-50. Used in the Monza
type cars by Chevy, Olds, Buick and Pontiac. I think they came out in 75 or
76. Also used in the Chevelle and Olds F-85 and some Vega's. They may have
been in some Vettes?? It has a different shift pattern from the newer 5
speeds, First is over and down. Fifth is under fourth. It's a small
lightweight unit with a similar OD to the Chrysler and Ford built 4 speeds.
For what it's worth, lived with two of the Chrysler built 4 speeds. One in a
77 Volare, one in a 82 GMC pickup. Both failed with the same problem. OD
gear starts whining. When you pull it apart fourth gear, the cluster and on
the Volare the input shaft and output shaft were shot. Very expensive parts.
Another option would be a Camaro or Mustang T-5. Especially if it was behind
a V8. Jeep and others use the same transmission.
Hi, thanks for the info. The T-50 would be nice, but I think it's a top
loader and may be too far back in the console (like the T-5 and T-56). I
was thinking if I could use a side loader like the MY6 there would be a
chance to bolt it in as a direct swap. The one I was looking at was named
the NP440 O/D 4 SPEED from a mid 80's Chevy truck. It was sitting in a 57
truck behind a 283 and all the shift linkage swapped right over (I think
they had pulled out a Saginaw 4 spd). The length and output shaft were ( I
am told) the same as a TH350. If they are prone to gear whine and failure
I may just stick with what's in there. Thanks again.
The ratios are :3.090 1.670 1.000 0.730
That first gear is a stump puller. You're going to surprise a BUNCH of
people at a few stop light grand prix because you'd have to have a 4.98 rear
end with the stock transmission to get the same effective ratio, assuming
the Muncie has the 2.20 first gear. It will make 180 hp perform like you
have never seen. The step from 1st to 2nd is SO wide you probably won't be
happy with performance after you shift though, because it is going to take
the engine out of the optimum torque band. The Muncie ratios are closer and
keep the engine in a narrower torque/rpm band with shifts. You may want to
look at an alternative - swap out the rear end. It may not give you the
engine speed reduction you're looking for (e.g. - if you have a 5.55 rear
end now, you need to drop to a 2.59 and I'm not sure there ever was one that
low - maybe someone else can say for sure).
The transmission swap will work. At the most you're going to have to adapt
the mounting bolts for the tranny to the support (I think the bellhousing is
the same pattern), tinker with the shifter and linkage, and maybe buy a new
custom drive shaft which is no big woof.
Please post your results here if you move forward with the tranny swap. It
would be interesting.
Hi, thanks for reply. On the highway at 80 mph I know it's over three grand
and guzzling gas. A little background may be need for my logic. Last year,
the car was pretty much restored as far as paint, interior, steering, and
brakes, ect. I had gone lightly through the engine, ball honed it, replaced
the cam (with a stock one) and hand lapped the valves. I knew that in
California on January 1st of 2005, the car would fall off the rolls of
emission standards. So I was all pumped up to spend some cash and make some
power. But alas, my fair state changed it's mind and listed the car as a
permanent resident as a "test only" vehicle. I was just sick over the whole
deal and wanted to just sell it. But my wife and daughter spoke up, they
love that car and drive it all over the place. They could care less how much
power it has as long as the radio and A/C work. I figured if final went
from 1:1 to 0730:1 and could avoid cutting the tunnel up and working too
hard it might be a good idea. Thanks.
this is what I put in mine NO REGRETS
they have a calculator on site to tell you the rpms after install etc.
A COMPLETE DEAL , all the parts are there
ask me any questions
Just for ha ha's I wrote down what the C6 does under a lets let her rip
moment. At 1,600 RPM in 6th gear it runs 65 MPH, but to push it you got to
go back to 5th. You get that same 65 MPH in 5th gear at 2,000 RPM. The 4,000
RPM gets just about 130, 5,000 shows 160 plus, and I run out of balls just
over 5,600 RPM with the speedometer (HUD)showing 182. I can be off on the
RPM a few, they are a bit harder to read than the digital speedometer. Three
times now I've hit the rev limiter and don't like that sound, I'd much
rather have a large digital tach in the HUD that the speedometer, or maybe a
Just to jerk you straight while you're diving that fast, two days later
coming home I saw 2 deer in less than a mile, one of which crossed the road
in front of me. No that's not where I let it loose, I try to pick my roads
with a little better chances for the public and myself. It was getting 26.7
MPG before that, I love Kansas. ;-]
Hi, Thanks, excellent sites. Weavermill didn't mess around cutting corners.
In a sudden passion for the hobby I may take the plunge, but I am probably
too cheap and lazy right now. I will wait and see if something breaks and
forces my hand, otherwise, color me yellow :) thx
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