manual to automatic transmission swap

[kelly cotter]

Hello. I have a 1967 chevy short bed with a saginaw 3 speed that needs rebuilt the transmission man wants 700.00 to rebuild he says 3rd and reverse gears are bad along with the syncros seams hi to me,i was thinking about converting to a auto,350 turbo what is needed to convert any info would be great have a good day Kelly Cotter

[71meangreenc10]

Crossmember, linkages, possible drive shaft yoke, oil cooler lines with a radiator, probably a few little things I am missing.


Smitty

[kelly cotter]

will the drive shaft need shorted

[Smitty]

Steering column, starter, rewire the neutral safety switch/backup lights.

[rsavage]

More than likely. You will also need a flex plate, an auto radiator with cooling provisions or use an auxiliary cooler, and will have to remove the standard transmission/rear motor mount crossmember. Why don't you look for a used 3 speed?

[kelly cotter]

thank you

[ivanuf2]

What about the pedals. Do you need to change them? Or can you just remove the clutch.

[cparman]

This is a project. Iam a big fan of automatics in our trucks.

A rebuild trans
an automatic crossmember
a radiator for an automatic or a trans cooler in front of your existing radiator
an automatic steering column
shift linkage from the column to the trans
an automatic flywheel and the bolts ( check torque spec for the bolts )
If you use a th350/400 a vacuum source from the engine to the trans
Trans cooler lines.

Ask me how I know this

Went from a Three on the tree to a 700r4
a bit more than the above, but sexy as hell when done!

[68anniversary]

Originally Posted by rsavage

More than likely. You will also need a flex plate, an auto radiator with cooling provisions or use an auxiliary cooler, and will have to remove the standard transmission/rear motor mount crossmember. Why don't you look for a used 3 speed?

I'm doing this swap right now. Can you leave the cross member in or can you safely remove it and use the auto cross member?

[Hubscrub]

yes, you will want to remove the manual crossmember, it got rivits that can be a butt, and buy or make you a auto crossmember

[LilD]

It would probably be more cost effective to find an old GM parts car/truck with an automatic in it rather than buying all that stuff. When I did the swap in my 69 I got an old Nova junker that I took the trans and related components from. I used a floor shifter and seperate trans cooler because it was easier. There are 2 different tail shaft lengths on a th350 and I dont remember which I used but didnt have to change anything on the driveshaft.

[71tahoe]

Leave the engine in the same location and a short tailshaft 350 will use the same driveshaft and yoke.

You can probably find another manual trans and bellhousing in good working condition for less than $100.

[rsavage]

I'm pretty sure that the yoke for a 350 is a 27 spline and the standard is like an 11 spline.

[LilD]

Originally Posted by rsavage

I'm pretty sure that the yoke for a 350 is a 27 spline and the standard is like an 11 spline.

Thats weird. Wonder how mine worked then.

[71tahoe]

Originally Posted by rsavage

I'm pretty sure that the yoke for a 350 is a 27 spline and the standard is like an 11 spline.

I'll claim ignorance on the 67. 69 and 71 definitely interchange from a saginaw 3spd to th350.

[raycow]

3 speeds before mid-60s were 16 spline. After that, most of them were 27 spline except for HD transmissions like the T-89.

Ray

[raycow]

I agree, the cheapest way to get the truck running again would be another manual gearbox. Don't rebuild it - just swap in a used one. It's not like they are scarce.

Ray

[Old school choppers]

I have a 71 P 10 step van with a three on the tree looking to convert to turbo 350 or turbo 400 wondering do I need to change trans crossmember or motor mounts

[motorcritter]

If you're going to go auto trans, might as well get a 700R4- it'll have an overdrive and work great. Overhauling a three-speed is not that difficult, and as noted, a replacement isn't that hard to source.
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[Old school choppers]

Originally Posted by Old school choppers

I have a 71 P 10 step van with a three on the tree looking to convert to turbo 350 or turbo 400 wondering do I need to change trans crossmember or motor mounts

yes I understand that transmission would be great my question is so what do I need to change over as far as cross members and mounts

[Old school choppers]

71 P 10 step I'm wanting to know if the stock transmission crossmember will work for automatic and standard both