OK I am confused about my trans

[mrsmothers]

I have a 1971 chevy long bed that has a 3 on the tree. Well had a three on the tree as of today its in the trash.

I have a muncie 4 speed to put in it first off I have no clue what type of muncie I have. I the numbers on it are 3901131 gm 30 there is also 65452 and h218 the shift knob has L 123 R on it.

Next question how do I put it in, where do I drill the hole in the floor will the drive shaft work, will the bell houseing work is there a place that has step by step pictures.

I am trying to get this in this weekend so any help woult be great

[airdale94]

I'm pretty sure you are going to need some parts. Bell housing, trans. cross member (there are at least 2 for the bell mount X-member, small block V-8 and 6cyl.), and your drive shaft will need the slip yoke ( from the front) removed and probably lengthened or shortened.

I'd look for another 3-speed or a car 4-speed. Or dig out your 3 and rebuild it. What exactly is wrong with it?

[mrsmothers]

It was just a three on the tree and they always hang up. I already have the 4 speed and would really like to make it work from what I was told when I got it, was it came out of a later 70s c 20.

[Boog]

I had a 78 chevy step with 3ott. It broke and I put in my Muncie close ratio 4 spd from a 69 Nova. It bolted right up. With the shifter handle removed I located where to cut the hole in the floor from the underside. I didn't have to relocate the crossmember or modify my driveshaft. Everything bolted right up. I had it in and out of the shop in under 3 hours.

[unreconstructed1]

Originally Posted by mrsmothers

It was just a three on the tree and they always hang up. I already have the 4 speed and would really like to make it work from what I was told when I got it, was it came out of a later 70s c 20.

You could always buy a floor shift conversion for that old 3. column mounted 3 speeds are definitely not a performance item, and as such can't be "power shifted", which is probably why it's hanging up. My '67 is a 3 speed, and I had the same problem for a couple of days until I got the hang of it, since then I haven't had a single hangup in about 4 years...

[c1069]

if you dont want to cut your floor, check this thread http://67-72chevytrucks.com/vboard/s...d.php?t=539222

[Hubscrub]

Unless you just don't want it you can fix the hanging up i'm sure. I bet a local race car owner would take that three speed off you hands. I sure miss mine i went to auto overdrive but i kept my manual just in case.

[geezer#99]

Probably nothing wrong with your 3 speed tranny. It's the linkage on the column that gets warn out making for missed shifts.
Measure the input bearing collar on both your old 3 speed and and your new 4 speed to see if they're the same. If the 4 speed is bigger you'll need a new bell. Some are. You'll also need a high hump tranny tunnel to put the 4 speed in. THe 4 speed won't fit under the low hump you have now. A high hump will have a hole already for the shifter.
A saginaw or muncie will be a bolt in. The sags input shaft will have 10 splines and you might not need to replace your clutch disc. Some newer muncie's had a 26 spline input so you would need a new disc. Be aware that a muncie or saginaw 4 speed put the shifter back real close to the bench seat so some mods are required to fit a handle.
You could use your 3 speed and install a floor shifter.

[wilbilt]

I had a 3 tree '70 C-10 some years ago. PO had added a cheap aftermarket floor shifter that was junk. I obtained the bushings to rebuild the column shift from the Chevy dealer for about $10. It worked flawlessly after that.

An added plus was that nobody ever wanted to borrow it, as they had no clue how to drive it. I do miss that truck.

[mrsmothers]

You know the funny part is I have 400 hp in the truck and that little three on the tree hasent blown up. But is there any way to modify my low hump floor pan to work with the muncie?

[wilbilt]

Originally Posted by mrsmothers

You know the funny part is I have 400 hp in the truck and that little three on the tree hasent blown up. But is there any way to modify my low hump floor pan to work with the muncie?

I think you would have to cut a giant hole in it to even bolt the 4-speed up.

[geezer#99]

Cut a hole and build a box. Probably easier to get a high hump floor.

[54belair]

I think putting the granny 4 in will be more than just a quick afternoon.

If you have 400 hp, how are you going to use it that you would want a granny 4.?

Just curious!

[mrsmothers]

to Just play around on the street the low gear is a 6.55 I think and first is a 3.58 which should be better off the line then the sagnaws 2.85 in first.

[54belair]

Well, good luck (seriously) to you.

I grew up with the granny low four speeds, they are a heavy duty work transy and in stock form at least they dont really lend themselves to playing on the street.

[mrsmothers]

Well I got the trans in and it is really heavy will the stock three on the tree bell housing be strong enough to support the sm465 ?

[LMREESE]

Originally Posted by mrsmothers

Well I got the trans in and it is really heavy will the stock three on the tree bell housing be strong enough to support the sm465 ?

NO! It will not. You are asking to break your bellhousing. I just got done putting a Ford t-18 granny in my truck and I had to make another crossmember to support the back of the tranny. I know a Ford tranny in a Chevy is complete sacrelige but I had the tranny and it bolted in with only minor modification and no adapters so I used it. I was going to make the hump for mine but found one cheaper than I could buy the metal. The old truck went down swinging, fought me every step of the way but finally got it in there and it's doing fine. I don't know about speed but with that 465 your truck ought to pull hell off its hinges.
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[mrsmothers]

I am haveing a really hard time finding a crossmember will one for a 4x4 fit?

[LMREESE]

Originally Posted by mrsmothers

I am haveing a really hard time finding a crossmember will one for a 4x4 fit?

Shouldn't be too hard to make one. That's what I had to do.
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