4spd Manual to Th400 swap.. Info / Help

[groundbound64]

Hey Guys/Gals,

I'm thinking about swapping my 4spd manual for a TH400. Just wanted to see if anyone has advice or has done this before. I've got a line on a new rebuilt Th400 with convertor. I assume i'll need a new trans-crossmember, cooler lines with aux. cooler or new rad, starter ??? ( no sure if manual will work on auto) and probably have to cut driveshaft or have a longer one made up and shifter linkage through floor.. Did I leave anything out ???

[MikeN]

I'm planning the same swap in a few months. I think you have it covered. You will definitely need a new starter if you're currently using the bellhousing mounted started like I'm using on my 3-speed manual.

[groundbound64]

I think your right.. I replaced my starter last year.. Now I rememeber that when I replaced my starter they parts store gave me one for an automatic and it didn't fit.. So.. maybe I will need one..

[414banger]

just did the same swap i went the cheap route and used the crossmember where the parking brake mechanism is located i tool it off fipped it over and bolted it to bottom of frame it worked perfect and motor was level and ye driveshaft will have to be shortened around 6 inches if i remember right goodluck to ya

[kieth]

What are you trying to accomplish with the TH400, just going automatic, or do you have a high HP ride for drag racing. If you are trying to accomplish better overall performance on the highway go to a 700r4 you will drop your rpms 30% cruising down the highway......Kieth

[BigDan3131]

Either the 700R4 or a 200R4 for better mileage. The 400 is heavy and eats up horsepower.

[koda360]

... But if you really wanna do it, I'll trade you my TH400 and tublar crossmember for you're 4speed... just sayn...

[61_FL_Apache]

I would vote for the 700R4.

[groundbound64]

Originally Posted by kieth

What are you trying to accomplish with the TH400, just going automatic, or do you have a high HP ride for drag racing. If you are trying to accomplish better overall performance on the highway go to a 700r4 you will drop your rpms 30% cruising down the highway......Kieth

I'm just not liking the manual on the truck. Plus when I run at 100kph (60mph) it's reving pretty high.. wanted to switch to auto for the convenience. My truck is not high HP.. going to be low and slow but would like to hear myself think inside.. Maybe i'll ask the guy about 700r. I know he has th300and th400's ..

[groundbound64]

Originally Posted by koda360

... But if you really wanna do it, I'll trade you my TH400 and tublar crossmember for you're 4speed... just sayn...

Ha, If you were alittle closer i'd probably consider it.. but 12hr drive for a swap is a little long..

[groundbound64]

Originally Posted by kieth

What are you trying to accomplish with the TH400, just going automatic, or do you have a high HP ride for drag racing. If you are trying to accomplish better overall performance on the highway go to a 700r4 you will drop your rpms 30% cruising down the highway......Kieth

Is there much difference in the install/parts of the 700r over the TH400 ?

[kieth]

NOT MUCH,

1. shorten driveline

2. get a manual drive gear to replace the electronic pulse speedo hook up

3. get a kit that allows use of the TV cable and electric switch for the Od shift.

4. crossmember

others here will know more than me, I installed a later model engine/700r4 combo so I had all the parts I needed except for the speedo drive.