Th350 bad ! How to change over to th400 question

[BCOWANWHEELS]

Well fellas my newly rebuilt (25k miles) TH350 went bad the other day. does fine till it shifts into drive then it binds up inside so i just parked it for a while till I can get to it. anyway I have a new th400 short tail shaft trans I,ve had for about a year now I was going to use in another truck. what all do I have to do to change over from a th350 to this th400 ? I know I have to get a new slip yoke. what else ? all help is greatly appreciated ALOT !
THANKS
BOB

[mightymouse]

does your 400 have a torque-converter .if you reuse the 350 converter youll probably need to have it flushed out

[BCOWANWHEELS]

I didnt know the torque converters was the same ! if any if the trans shops around here flush the converters then for sure i,ll do that or get a reman one from parts store. is the shift linkage the same ? what about the cross member ? also is the length of the trans the same or do I need to modify my front drive shaft ?
thanks
bob

[mightymouse]

i believe your cross-member is the same.your drive shaft may work when you switch the front yoke i don't know. you may also have to change bracket on side of trans for shift linkage sorry i'm not much help . hopefully someone who knows will chime in ...

[BCOWANWHEELS]

my friend just said i,ll have to slide cross member back a little to match the th400 mount. I,am gonna slide under the truck tomarrow and see if theres holes allredy for this. I think while I,am at it I,am gonna drill and make second crossmember ready for thru the x-member 2 1/2" exhaust pipes. sure would be alot easyer to get to with everything out.

[mightymouse]

yes the holes are there . i just don't know if your drive shaft may be to long .are if it will work with a shorter yoke . i know they make different lengths of yokes.

[Longhorn Man]

Pretty sure the shaft will need cut.
Kick down provisions will be wanted. The 400 has an electric one.
You may have issues with the parking brake cable.
The linkage is in the same location, but the p/n is t the same between the two. Not sure if you can 'make it work' or if you need the 400's linkage.
Look at your exhaust too.ight need to modify it to slide the crossmember back.
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[Longhorn Man]

A 350 converter will work but stall a little higher and reduce the fluid capacity. The cost of a stock reman unit is cheap enough that I would not risk it personally.
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[1972trucks]

i used the same drive shaft and also the same linkage stuff when i put a th400 in my truck from a 350

[billsbowtie]

bob i have a good rebuilt 350 trans out of a 71 lwb chevy. it,s clean still has rebuilt date on it little bill drove the truck it came out of from ga. to my house with no trouble it's been pulled out setting inside a couple years now $200.00.

[BCOWANWHEELS]

Bill, count me in on the trans. I,ll call you soon as your off line.
Bob

[BCOWANWHEELS]

Thanks fellas