seecookgo

Does anyone know what is needed to convert the auto tranny in an '80 to a manual? Any help with instructions or references would be much appreciated, thanks. :confused:

mrvette

In order to do that job, you will need to pull the entire dash assy. for starters, in order to get to all the bolts in the master cylinder/booster assy, then all the other ones, holding the steering wheel, which comes out, and then all the crash brackets up there holding the pedal assy in place.....then you probably will need weld a bracket to frame for bell-crank assy for clutch fork, then change shifter mounting completely, meaning cut and reform fiberglass on tranny tunnel, then change driveshaft...maybe the length, but certainly the yoke end into tranny....ned get an appropriate shift plate for console so it looks good....

in other words...forgetaboutit.....costs maybe 1500-=2000 bucks, plus labor......unless you get lucky in a junkyard.....

GENE

norvalwilhelm

I did this swap last winter in my 75. It required removing the drivers seat, removing the steering column which is really not that hard, then removing 10 bolts to get the old pedal assembly out. This is the hardest part, one of the brake booster nuts is a real pain. You then have to work the old assembly out. When I reinstalled a manual pedal assembly I put studs in the fire wall facing out, they are from GM and it made future brake asssembly removal a breeze. For a clutch you can use a hydraulic clutch assembly and it bolts right in. I used one from a one ton 85 truck but camaro stuff should work. Other then the padals it was not that hard. The drive shaft shortening is cheap about $45. Drop it off in the morning and pick it up at noon. The rear mount since you have a removable cross member is just welding and extension on the front. The shifter location might change if you use a overdrive 5 speed, the hole in the floor is almost right on, a little filing on on side of the hole in the fiberglass was all I need to make it fit. This is a winter project where you can take you time.
I really like mine. The pedals are the hardest part. Go for a overdrive. I ran a T5 for a year behind my blown big block then switched this winter to a Tremec TKO for reliablity. The T5 doesn't have a great reputation for reliability but I have one in my 11 second nitrous 355 mustang and one behind my blown big block and never had a single problem. It comes down to how to treat it. Don't power shift. Some guys can break anything behind anything. The overdrive is great with it's .68 overdrive.
It is a worthwhile swap. Tackle the pedals first and the rest is a piece of cake.

ImBatman

I am doing the same swap for my '71. Althogh I agree that it is easier with the entire dash out it is possible to do without going to that extreme. I also agree with Norval, once you swap the pedals the rest is easy. I bolught my pedal assembly for $125 from Gary Gurula. If you are running a th350 now and swap to a m20 or 21 the drive shaft does not need to be modified. If you go with a T10 you will have to swap the yoke. Slight modification will have to be done to the tranie cross member by welding 2 l brackets for the mount. Thier is a picture of this in the ZIP catatog. You will also have to weld the braket on the frame for the bell crank assembly. Your cheapest route would be to find a complete assembly from a junk yard but if not you can by almost everything new. IMO if you want a manual tranie go for it! It is well worth the effort. If you need any help feel free to shoot me an e-mail. This swap is very popular and several of us on this forum have either done it or are doing it. Good luck!

Jason Staley

I also did this to my 76. It truely is not as bad as it sounds if your at all experienced with fabrication, welding, and just general mechanical stuff. I installed a Richmond 5 speed (no overdrive) in my car which worked out great since it only had 3.08 rear end gears (5th kind of acts like an OD). Anyway here is what I had to do:

1) I installed a Corvette clutch pedal that I bought from Corvette Central. This is definitely the biggest pain in the project. Count on a couple of days to do this little job (including some breaks for back, nerves, hands, etc.) I did it in 2 afternoons after work. I had to remove the steering column and its support brackets (I think there are 3 or 4). Then you can remove the 8 bolts holding the brake assy in the car. Once it's out the pedal is a breaze to install. You also have to narrow the brake pedal - some sawing and/or grinding involved. Then I installed all new rubber pedal covers. Looks like the car came that way. :)
2) I bought all of the clutch linkage new from Corvette Central and they have a really good diagram that shows all of the parts you need and its a good reference when your trying to assemble the mess. Like was mentioned in an earlier response, you may have to weld a bracket on to the frame for the pivot rod - I did.
3) The floor board will have to be cut to allow the shifter to come through. I purchased the stock lower shift boot to seal out the fumes, noise, heat, etc. and fabricated a little patch panel. Worked out great.
3) Richmond told me how to modify the automatic trans mount so that was pretty easy, but it did require some cutting, welding, grinding, and painting. It can all be done outside the car so it wasn't too bad - just some time.
4) I didn't have to do anything to my driveshaft. If anything it's probably 1/2" too short for a perfect fit. I fix that when I upgrade the drive shaft, but until then it's working great. Who would have thought that a 350TH driveshaft using a 400TH front yoke would be almost a perfect fit for a stick. :D
5) Also check to make sure your engine has the hole drilled and tapped for the crossbar pivot bolt. Its in the block just forward of the oil pressure sending unit. This could be a show stopper!!!
6) The hole in the floorboard for the clutch push rod from the pedal was already in my car, so all I had to do was buy the little rubber boot. It's just below the brake master cylinder. Some thing else that could be a pain if the car doesn't already have it.

All in all, it took my all of a week to do the change over, but it was well worth it. One note of caution: If you go with a Richmond 5 speed it is clunkier (is that a word??) than the newer sticks such as the T5. Good transmission, just but built more for the racing than the street.

If your at the cruise-in III this year, I'll be there so you can see how things turned out. I have a lowered white 76 with 17" aluminum rims on it.
Here's my home page (hope it works - just built it). http://temp.corvetteforum.net/c3/greatwhite/
Good Luck :cheers:

norvalwilhelm

You also have to narrow the brake pedal - some sawing and/or grinding involved. Then I installed all new rubber pedal covers. Looks like the car came that way.

If you have to cut the brake pedal that means you bought the pedals for a ? to 78 or 79. I think in 80 the pedals had a smaller brake pedal so make sure you get the correct ones. The ones that are equal in size are for 78 or 79 and older.
As for cutting a hole in the floor for the shifter I was lucky since it was already there and had a factory cover plate. Even the hole in the firewall was there under a cover. A stock hydraulic master cylinder fit perfectly into this linkage hole. Even the mounting holes were already there.
If this is a winter project and you take your time, one problem at a time it is not hard. Rush it and it will seem difficult.

72 Stingray

Norval,

What bellhousing are you using with your TKO?

norvalwilhelm

The Tremec TKO's are a ford transmission and some companies are modifying them for chevy. If you buy a Chevy Tremec it will bolt directily to the stock chevy bellhousing. I used a ford Tremec and with the aid of a 1/2 inch adaptor plate it bolts right up to the stock chevy bellhousing.