The Stovebolt Site Forums The Shop Area Engine Shop auto trans to manual

Hi

Can anyone tell me what modifications I have to make to change a 9 inch tail 350 turbo to a 4 speed manual overdrive in a Chev van.?

Will the manual Dodge or Mopar type 4 speed fit in place of the 350 turbo thats there now without changing the driveshaft or will I need to change the driveshaft and if so what drive shaft will work.?

What about the crossmember is it the same for both transmissions.?

My van is only 25 years old, but I have a 292 engine running it, I think that it will do good with overdrive.

Chevy,

It's pretty unlikely that your original driveshaft will be the right length. The only way to tell would be to know the length of the new transmission. Also, you would need to know if you're going to use a mechanical or a hydraulic clutch -- 350s built for automatic transmissions don't have the boss on them for the Z bar.

These forums are mostly dedicated to trucks pre-73. You'll probably find more people with experience on '77s in http://www.67-72chevytrucks.com

Brian

I don't recall that the turbo 350 came in more than one length. Did it?

The Saginaw and Muncie transmissions that were common in 60's and 70's cars were all the same length as a Powerglide, which I thought was the same length as a TH350.

If your van is the same as the '75 I once owned, the distributor is at least as far back as your knees are forward. Give or take a bit. The bellhousing would be a little further back, and the transmission winds up about even with your seat.

The shifter would be somewhere further back, almost behind the driver. You'd need a special shifter or maybe some wild linkage to make it work...

Pull the engine cover off and look at where the transmission sits and think about where that puts the shifter & linkage.

Any manual transmission replacing an automatic is a giant leap backward in technology. If you want an overdrive, fit a 700R4 in place of the TH350. It will require fabricating a driveshaft, and possibly tinkering with the shift linkage a little, but it will be mucs simpler, and perform better than a stick shift. Non-GM transmissions won't bolt up without extensive modifications.
Jerry

The overdrive transmission I plan on using is a 4 speed and it was available in GM vans and pickup trucks from 1982 and up, and the shifter is on the floor not colume, it comes up next to the doghouse in a van like mine.

I still don't know about the crossmember,? by the last few posts I would think that the transmission will fit in place of the 350 turbo.

As for putting in a automatic overdrive 200R4 or 700R4 I don't like that idea, they have a poor track record.
I would rather go stick, lots of folks on this site are going backwards when it comes to there vehicles these days thats what this site is all about.

The overdrive transmission I plan on using is a 4 speed and it was available in GM vans and pickup trucks from 1982 and up, and the shifter is on the floor not colume, it comes up next to the doghouse in a van like mine.

I still don't know about the crossmember,? by the last few posts I would think that the transmission will fit in place of the 350 turbo.

As for putting in a automatic overdrive 200R4 or 700R4 I don't like that idea, they have a poor track record.
I would rather go stick, lots of folks on this site are going backwards when it comes to there vehicles these days thats what this site is all about.

TH200-4R and TH700-R4s have excelent track records. just some of the early ones had some issues

700R4 not strong for pulling everyone I talked to about it says the same thing.

Why ask for advice when you've got your mind made up, and don't intend to accept anyone's suggestions? MOPAR transmissions don't fit GM vehicles. Where did you get that idea in the first place?
Jerry

They did make a mopar style transmission to fit into GM trucks in the 1980s.

And I still don't know about the crossmembers if they interchange on the two transmissions.?

You better look that one up Hotrod before you try doing character assassination on people.