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trans. conversion, feasiable?



I 've always had 4-speed trans., but the recent purchase has a (good) 350 auto.
I'd like to swap but with the computer interface and a rewiring project completed today in my console, I'm pessimistic about the feasiability. anyone have any experience or input on this project for an '81?
regards, Jim

Aside from the ECM auto/manual change over, the biggest challenge will be to find the hardware to mount the clutch pedal mechenisim both inside and to the frame. I'm sure it can be done but I would think it might be a good sized project.
you will need help with the welding, if you can't do it yourself. also, to save yourself lots of headaches, make sure the 350 motor if not original, has the hole tapped and threaded on the drivers side for the pivot linkage to mount correctly. if you are planning on tons of horsepower, remember the rear end was not designed for it and may require some attention. most C4s had the dana 44 with the manual transmission.
thanks for the comments,, just wishful thinking on my part...motor and trans are stock original...will likely live w/it. thanks.

I’m preparing to convert my 81 from auto to M21. All the parts are available, Art’s has the bracket that bolts to the frame for the Z bar plus a lot of other stuff, Eckler’s also has a lot of parts you will need. All the parts are out there you just have to find them. As far as feasibility goes, if you really want the manual trans in
your vette feasibility of the project is not an issue.

Don’t forget you will also have to replace the U joint caps and bolts on the half shafts and rear end yokes, possibly the drive shaft and maybe the cross-member. I have read that the automatic drive train is not strong enough for the manual trans.

It’s definitely a huge project; I still need the bell housing, cultch, half shafts (replacing) drive shaft? and cross-member? once it all comes together it will be worth it.

If anyone knows whether or not the drive shaft needs to be shortened or lengthened or if the cross-member needs to change or if anything I have stated is incorrect let me know. All the research I’ve done on this project indicates that all these changes are necessary, if not I would like to know.

Yes They Are

The trans length is different which means a new or modified driveshaft and crossmember, yoke etc. It will also mean welding, and possibly drilling the frame for the new crossmember. I've done a few of these conversions, but they were some years ago and a whole lot easier with less to contend with. As you said, you will then have to contend with the auto rear, ratio, strength etc. My honest opinion, I'd think VERY seriously about leaving it alone and living with it. It is a MAJOR project, not something I'd consider without a lift, working on jack stands and your back is gonna get to ya. I think I'd sell and buy a standard. Good Luck!

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