Yeah, I searched. I'm sure this has been asked a hundred thousand times, but manual/transmission/gearbox/swap/conversion brings up a million off-topic threads. So, if anyone knows of a relevant thread, please post a link.

I've got a 1980 3spd auto that I want to swap to a manual. Buying a manual wasn't an option where I live, the cheapest 78-82 manual in Australia was literally double what I paid for mine which is in better overall condition.

I'm still trying to figure out what my options are. The engine is unoriginal, so I have no issue going non-OEM. I've been looking at the prices of new gearboxes; about $1,700 for an M22 is the cheapest I've found (is that about right?). I've also been looking at ZF 6 speeds of which there is a brand new one for sale nearby for $2,400. I have heard that the swap is not easy though, and I would like to keep it as easy as possible.

Would an M22 4spd be the best/most cost effective/easiest install option? Where's the best place to look for one new or used?

 

It is really no big deal to make the conversion, I changed mine over last summer. This year I bought a 5 speed Richmond off of another forum member. The pedal exchange is the most difficult part of the conversion. My car has a 3.08 rear gear so with the new 5 speed it is like having a 456 rear gear but still 1 to 1 in 5th, the best of both worlds.

 

That's something I DO need to learn more about; the gear ratios. I have a rough idea, but not exactly. I'm kinda interested in a 4spd because I love the feeling of torque, and feel I may enjoy winding it out in a long gear more than thumping through a 5 speed. I love the long, solid throw of the 4spd shifters too.

How is the five speed to drive? Is it a comfortable shift? Way better than the four? I think the Keisler PerfectFit kits look like they'd be pretty easy to drop in. I've read they're up around the $5k mark for the full auto-manual kit. A bit more than I was hoping to spend just on the parts, but doable.

What sort of power will the M20/M21s take? They're quite plentiful near me, M22s a bit harder to come by. I've heard bad things, but it might do just to get all the pedals etc. wired up and I'll worry about a better box in the future when I really start playing with the power. Will they take 250-300 wheel HP?

 

both the m21 and m22 are more than strong enough for twice that power

 

Some of us choose to go the 5 speed OD route. I like the idea of having lower RPM's on the highway. You can go with a Ford T5 or a Chevy T5. If you go with the right year on either of these you're good for 300 torque. I'm just getting started on this so not an expert but I'm buying parts now, will do the job in the winter. Like you said, there are a lot of threads on the forum discussing this topic.

 

Sorry, i meant to say the "cheaper" 5 speed OD route. Keisler is out of my budget right now.

I too have a auto today, I'm thinking I can do the whole swap for about $1500.

 

If you do any driving on the highway at speed the 4 speeds are a thing of the past. Why not put in a 5 speed and have the best of both worlds. Great gear ratios for acceleration and an OD for nice highway driving. I have had them all in my car, started with a Muncie 4 speed with different rear ratios. Then went to a 5 speed. Best upgrade I have ever done to the car. i now run a T56 6 speed and it is even better than the 5 speed. Have you driven the short throw shifter on a rail type shifter? They are so much nicer shifting than the older style shifters for sure. The T5 is a low cost 5 speed, i have installed a bunch of Keisler kits and they do pretty much drop in without any trouble. Everything is there and there is no sourcing of the parts. You can save some by sourcing it yourself if you have that type of capability. Good luck with what ever you do and the forum is full of answers if you run into a problem.

 

I would like a 6spd... I'm just worried about too much custom fab etc. Does the T56 bolt straight in? If not, is there much work/moving of stuff to do? I want something that will come through the original console hole with little effort. Do the T5s go in that easy?

I've since found some threads on the 5spds. Not much on the 4spds though; I guess people just buy a factory manual there. I've read that 3rd breaks in the T5s a lot, which is not good as the shift from 2nd to 3rd is the one I'd do the most with the power down around here. There really isn't that much power yet though, so it might do for now.

What other good options are there for 6s? Just the T56? I don't want to go down the ZF route from what I've read; too much moving of stuff to get the shifter in the right place.

 

No the T56 is definitly not a bolt in operation. There is not enough room here to write for all the stuff I had to do. I did do a little extra but the T56 is a BIG transmission and it will fit in the tunnel but that is about all that fits. Many fabbed up parts and accessories. The T5 which I have not done is a much better fit as is the Tremec 5 speeds. The Richmond gear boxes are pretty good also. I have never done one of them either. The standard T5 is pretty weak if you drive it hard with some HP and that sounds like what you want to do. The World Class T5 is stronger and some have done well with them without exploding them.

 

Others on this thread have already recieved my job narrative and parts list for the four-speed swap. PM me with your email address if you'd like a copy. As for the M20/21/22, as I understand it the ratios are the same for the M21 & M22 but the M22 has straight-cut gears and is therefore a little noisier than the others. I have an M20 in mine and like it fine but with the 3.08 rear it doesn't make sense to beat on it so I don't. If you're going to abuse yours and have lots of power you're probably going to want a shorter (higher numerical) rearend gear or a five-speed. T5's won't reliably take abuse; they were never made for 400+ horsepower in a 3300 lb. car. Richmonds, T56's, TKO's were. All up my M20 swap cost me about $1900 with the trans completely rebuilt and new clutch, shifter (Hurst), etc.-it pretty much depends on how much you have to spend. Obviously the best solution would be to have a bulletproof 6-speed with short ratios in the first four gears and a sky-high overdrive for economical cruising but not everybody can afford that. At any rate the worst manual trans is better than the best automatic, and four gears are always better than three, especially if I'm rowing them around myself!

 

Here's what i'm in the process of doing:

I have a mostly stock '81 auto. I'm going to go with the Keisler RS500 kit, but instead of buying the whole auto to manual swap, I'm slowly buying 4 speed parts, so when I have everything i need, I can order the much less expensive manual to manual kit. I've already found a used pedal assembly and a 621 bellhousing for a lot less then buying them new. since my engine is mostly stock i'll get good quality replacement flywheel and clutch set, and everything else is just little things after that. I'm going to go with a hydraulic clutch set up though. I figure it will be easier to fit then the manual linkage and be less of a headache during install.

 

Nice, please keep us updated.

I'm thinking of doing my manual swap in my 76 L-82 that has a TH400 today and putting in a 90 Camaro Z/28 T5 from another guy who had it in his vette. Buying used pedals, bell housing and linkage from another guy. Any going with a new clutch that someone else on this forum said is easy to use from summit, staying away form hydraulic for now though. Can't wait to get started.

 

Yeah, one of the purpose made kits, like Keisler, is looking like a good option. The problem in Australia is a lack of knowledge on Corvettes, so I think getting something odd that needs lots of custom work is not such a good idea. I need something that is simple enough for a competent mechanic who has never done any major work on a 'vette before to handle.

Has anyone ever heard of a Supra 6spd being used? Because they're plentiful around here. Strong too, plenty of 1,000hp Supras here running under 10 with the original box. Probably not a good idea to try to be a first though...

M20s and M21s are also common as Holden used them back in the day.

I guess the next step is finding some local mechanics and asking them what they're confident doing. I can tackle a bit on my own, but I don't have a hoist or anything.

 

Aloha's,
Just completed my auto to manual swap,time and money well spent! Vette is a blast to drive ...Kinda like your girlfriend with new and improved *****! Almost as much fun ,anyways here's the link to my write up....http://forums.corvetteforum.com/c3-t...am-change.html

 

Your 80 has a 3.08 rear end (if it's original). Forget about a close ratio muncie, it will be a dog out of the hole. One with a 2.56 1st would be ok, but dont expect to tear up the rear tires.
A Richmond 5 or 6 speed would be a pretty much direct swap and have 3.28 1st gears which work well with a 3.08 rear.

 

Gary's right on the money! That richmond with a 3.08 rear is perfect....Aloha's

 

All the manufacturers today install overdrive transmissions in every car. There's a good reason for that.
Look into a Keisler overdrive trans kit, if your budget will stand it. The kits are very complete, so you won't get stalled in the middle of your project. And the available ratios are such that you will get improvements in both acceleration and fuel consumption.
As far as putting a Toyota transmission into a Corvette,
Aaaaaaaaaaaaaaaaaaaah!