Doing a 6spd swap to a TH400

**00BlackBird** · 09-29-2009, 11:12 AM

What all do i need ?? I know i need a stall,driveline,crossmember, and flexplate anything else that is lil stuff im forgetting ???

**GONZO SS** · 01-06-2010, 03:44 AM

I was thinking on doing the same swap,have u had any luck with the swap ?

**Too Fast** · 01-06-2010, 03:55 AM

I don't have any advice, but I do have a ? Unless you're making your car into a race car, why would you do this swap. Lose double OD of the manual trans??

**GONZO SS** · 01-06-2010, 08:02 AM

Thats what I have in mind pluse adding a gear vendor

**gnomee** · 01-06-2010, 05:53 PM

I also question the reason for doing this?

That aside.. You will need a new console, a new radiator and I think a new PCM or a re-program.

**Goldcuffs** · 01-06-2010, 06:05 PM

Just my 2 cents but they can build 4L60E's and 4L80E's to handle quite a bit of power. There's really no reason to use that old junk any more.

**AKA Speedy** · 01-08-2010, 09:05 PM

Originally Posted by Goldcuffs

Just my 2 cents but they can build 4L60E's and 4L80E's to handle quite a bit of power. There's really no reason to use that old junk any more.

true... just look at Performa built.

I'm not sure how the prices vary though. Old may be cheaper?

**408WS6** · 01-09-2010, 02:57 AM

I did a TH400 swap from an M6 awhile back. It seems like a used:

1) TCI Flex plate specically for TH400/LS1 interface.

2) New crossmember, I got mine from BMR, but I've ready where you can just modify the old one by drilling oblong holes, need to verify this.

3) New driveshaft, or need to replace the yoke end of your old one, while getting the length right. If you still are using the stock aluminum DS, you should go ahead and buy a new one. If you have enough power that you need a TH400, then chances are you stock driveshaft will not last long.

4) You'll need a new shifter. Mine is a B&M, I like it. Have fun installing it though.

You won't need to reprogram for PCM. You also won't need a new console. TH400 fits right up in there.

5) They make special bell housings now for the TH400/LS1 interface, I highly recommend buying one, although you don't have to. There will be a bolthole or 2 that won't get used if you don't.

6) New converter.

Thats about all I can think of...

You should also think about a speedometer sensor...

**408WS6** · 01-09-2010, 02:59 AM

Also, unless your car sees mostly track use, I would not recommend the TH400. Its not nearly as fun driving around on the streets as an M6, but if you drag race alot, and have alot of power, then it makes sense. I kinda miss my M6, but my car mostly sees the track and I got tried of replacing clutches all the time.

**408WS6** · 01-09-2010, 03:01 AM

If you decide to go 4L80E, then the only difference is price. But with the 4L80E, you WILL have to get another PCM, unless you shift it manually.

**Hi-Po** · 01-13-2010, 12:41 AM

Originally Posted by 408WS6

If you decide to go 4L80E, then the only difference is price. But with the 4L80E, you WILL have to get another PCM, unless you shift it manually.

Not true. A 98 ECM will not control the 80E. A 99+ ECM will. Flashing the ECM with the approprate OS and buying the correct harness,connecotrs WILL work. A 4L80E Trucks operating system will work.

**408WS6** · 01-18-2010, 09:47 AM

Originally Posted by Hi-Po

Not true. A 98 ECM will not control the 80E. A 99+ ECM will. Flashing the ECM with the approprate OS and buying the correct harness,connecotrs WILL work. A 4L80E Trucks operating system will work.

I guess I am alittle behind. A couple of years ago when I looked at it, the common thinking was that you had to use a stand alone controller for the 4L80E. Turns out the 99+ ECM's will work. It doesn't matter now, if I do anything different than what I already have, it will be to go back to an M6.