97lt1stroker

iTrader: (1)

Hi all I am looking to swap my 97 LT1 car from the T56 to a TH400. I so far have the swap cross member. I know I need, short tail slide in yoke th400, zero balanced flex plate(I have internally balanced 383) torque converter, trans. cooler and lines, shifter and cable. I will be using a MWC tunnel mount torque arm. I already purchased a QP 9"also need driveshaft(will manual one work with new ends or too short?)brake pedal assembly. what else do I need to do swap? what for speedo? nuetral safety switch? I have read plety on swap the other way around that talks about cutting holes in firewall. I assume no need to do this for me? also I am selling all T56 stuff I will be pulling out. trans, bell housing, pedals,clutch,flywheel, driveshaft if i cant use, cross member etc. New MGW shifter. thanks for any help.

SwampWS6

iTrader: (7)

Nice car.

I have done the swap myself. You will need a custom driveshaft or find a company that makes one for this specific application. I have a speedo sensor from Bill @ BP Automotive for like $55 shipped. But I also have his custom wiring harness as well, so everything was plug and play for me. I kept my clutch pedal for ***** and grins and I havent had to cut a hole in the firewall at all. The key points are crossmember, driveshaft and speedo gears. Seems like you have everything else covered.

Good luck, hope this helps!

VoyagerCamaro

How much for the T56 trans only??

BTC

NNNNNOOOOOOO. Don't do it.

Dirty_Bird

Neutral safety switch you have to wire in. I know 4l60e to th400 i cut harness and wired acordingly. For speedo cut pigtail off speed sensor wiring and connect to front abs hub. Tune and walla your done

BIGsmokey10

iTrader: (3)

It aint bad.

If i remember right my ds was 33 3/8

I run my Speedo off the vss sensor in the tail of the trans with a 375 output shaft

Hipster is the best all around vb for the money. Griner is the best but pricey.


U can take a t56 cross member and actually slot the hole for the trans mount back a quarter or so inch and it works perfect.

Dont chimp out on a converter.

Dex 3 is the thinnest fluid with type f in the middle and jd hygard being the thickest.

Get a good 34 element sprag, 80e forward hub, stock shafts with good clutches and kolene steels and you will have a 3 speed that will handle your combo.

Also a brass element filter.

That about covers the majority of it.

If you have any questions ask and i can maybe help

ahritchie

iTrader: (1)

6 speed to a 3 speed? Seems like a big step back IMO. It would be more impressive to still be slightly slower with the stock 6 speed IMO and still have 2 overdrives than to have a fully built 383/th400 combo that still runs 11s... not to mention the advantages in gas mileage, better controlled handling, lower RPM highway driving, overall badassness of the T56!

97lt1stroker

iTrader: (1)

thanks for input. If i was keeping as a street car i totally agree. But car will be 90% track car no concerns with mpg. Only driving it 1/4 mi at a time. Th400 much better track trans

warriorcustoms

iTrader: (10)

If Your gonna drive it At All on the street I would go 4L80E!!! Best of Both Worlds Thats what My 396 LTx is gettin... Core is layin beside tons of good parts for the build... But I wanna be able to drive from the house to OKC or a drag strip or 2 thats close by...

Puck

iTrader: (17)

4L80 is a heavy, expensive beast.

Losing OD is well worth the trade offs of weight, price, strength, and ET if its not a street car.

97lt1stroker

iTrader: (1)

Okay thanks for all the input so far. I have a couple more questions now that i am a bit further along. I again am putting a TH400 in my LT1 383 internally balanced. I now have my Transmission which is the 34 element sprag race built with Alto red clutches in all 3 gears, RMVB and trans brake. question is my trans guy said and you can see in photo speedo gear has been removed. can I hook up speedo? looks like not. someone mentioned hooking up to abs but that is all getting deleted with manual brake install. (track car) also how do I hook up Nuetral safety switch(T56 was removed) is that the 1 wire spade connector? as seen in pic. and I am pretty sure I have the right flex plate. it is a TCI pn.399174 which on Summits page says for internal balanced 1 pc. rms LT1 but says application in for 4L6E. http://www.summitracing.com/parts/tc...4/applications
all I read seems like the same one for the Th400? also a few pics of my new rear. QP9" with 3.70 Yukon 3rd member with spool.

BIGsmokey10

iTrader: (3)

You splice into the factory safety switch. I can take some photos of mine this week. Its 2 wires iirc.

Your speedo hole is covered, and your ditching your wheel speed wires so youll be screwed there.

I don't think you'llhave a speedo!


Looks like a transmission specialties brake

97lt1stroker

iTrader: (1)

thanks for reply. TS brake good?
I'll Pm my # if you can text me thos pics. whenever you get a chance. I am in no hurry.

Nostang

iTrader: (4)

Yeah, if the gear is removed you are SOL for hooking up a VSS sensor. It would be nice if you could get the trans guy to install it for you before you drop the trans in. The flexplate in the link will work but make sure to check your converter bolt spacing to make sure it is 10.75". I am not sure if I ever wired in my NSS as it has been so long so I won't be able to help you there.