O.K. I am looking swapping out the M6 in my car and going to a TH 350 or 400. I know that the 400 is stronger, but heavier. What I need to know is how much of a pain was the total swap, what had to be done to the computer, how did you get the speed/odometer working properly, and what was the total cost of the swap, shifter, tranny cooler, driveshaft, all that nonsense? What converter did you go with, I plan on keeping the car N/A, probably going to a cam along with the rest of the bolton's I'm missing shortly after. Also, who did you buy the tranny from, and how much did you spend on it? The issue I am having is that I am inconsistant as hell at the track, and I really don't think that I will ever shift the car as hard as I need to to get it to run what it is capable of, am afraid I will break it. I'm looking to get the car into the 11's I'm not looking for 9 secind slips or anything like that. I already plan on subframe connectors, shocks, 12 bolt and relocaionbrackets over the winter, so the weak links will be out of the way. ny feedback would be appreciated.

 

Not to bad of a swap. I bought my TH-400 set up through MadMan. He use the TransKing tranny and converter. His kit came with everything needed, except shifter - I went with the TurboAction Cheater. Tranny, converter, cooler, driveshaft, flex plate. You can use your M6 cross member - you'll have to put a "cunk" of metal inbetween the tranny and cross member. Your traction arm will have to be changed/ modified - the TH-400 does not have a place to put the TA.

No speed-0-meter - don't need one. Nothing needs to be done with the computer to make it run. You'll throw a couple of code for speed-o and such, but with LS1 Edit they are quick to disappear.

You can also do a search. This topic is very "hot" right now. Numerous trend on TH-400.

For the converter you can ask MadMan. I had a 4000, wasn't big enough. I just sent it back for re-stall to 4800.

Good Luck

David

 

David,

I know that Madman does have some good stuff. I do want my speedo to work, is there a way to get it hooked up and working,and will the odometer work too? The turboaction shifter, did it fit in the opening for the 6 speed shifter, or did you have to do some modifications? What did you use for a diveshaft, is the lenth any different? If you don't mind me asking, what did the whole setup run you? P.M. me with the pricing if you don't want to disclose to the world. I have the torque arm all set already, I went with a chassis mounted spohn unit, mainly because IMO applying force like that to the rear of the tranny can't be a good idea, to this day, I do not undrstand what GM was thinking there, and this swap was something lingering in the back of my mind after my first pass at the drag strip, some 3 years ago......

 

I just PM'd you

David

 

You need 150.00 worth of parts to make the speedo work + you have to scale the speedo a little different on an M6 car if you are converting, you will need a new driveshaft. You will get a few misc codes like 'no clutch use detected' and stuff like that but its easy enough to delete them with edit when they pop up. I wanted to keep the interior looking fairly stock so I used a B&M hammer shifter with the 6 speed console - works great. There are some pics on my cardomain site of how I blocked the hole in the floor. and mounted the shifter. Its an easy swap..

 

Get these parts from GM, it should cost about $200 total and it will bolt right in, no problem. You'll need to multiply your VSS signal by 2.5 to read correctly, auto do not require this speedo multiplication.

sensor: 8655291
reluctor: 8655315
pigtail: 12085498

 

KP- I saw the pic on how you covered the hole in the floor, did you have to cut a new hole for the shifter? Maybe I am missing something. I don't want to cut up my car to make a swap like this if I can avoid it. I know it sounds stupid, but you can't buy these cars anymore, eventually they will be worth some money. I doubt that 30 years from now anyone will denote a car for having subframe connectors welded on, but the floor boards cut up... If anyone can elaborate as to the fabrication needed that woud be helpful. I before and after foor pic would be great.

 

If you have an M6 that big hole is already in the floor, I just covered it with an aluminum plate and bolted the shifter to that. I didnt cut any holes in the floor except fot the cable to pass through and the four 1/4" holes to bolt the plate down.

 

So the shifter itself is not mounted to the tranny. Is there a linkage going to the tranny? Pardon my questions, I've never seen a th400 out of a car before, and I don't know anyone that ever pulled the swap to one from something else.

 

The shifter is mounted to the floor and there is a cable that runs to the shift lever on the side of the trans. Couple more pics of the mounted shifter:

 

The arrow is pointing to the portion of the shifter that need to be removed in order to sit properly in the opening in the center console I assume. After the install is done, it looks nearly stock, other than the handle, which is exactly how I would want it to look. Thanks, now I know that what I want to do can be done.

 

I dont much care for the handle but you get used to it, I was just going to screw a regular round ball on it but never got around to it. I wasnt sure I was going to like the way the shifter worked at first, its looks kinda flimsy compared to stuff I'm used to but it works very well and I have had zero problems with it. The tabs needed to be cut off to get the console to fit over it, it comes with a little plastic console of its own and thats what the tabs are for.