swapping 267/th350 to 350/th400

[gold84gmc]

my dads truck (77 gmc stepside 2wd) had a 267 with a th350, were building a 350 to put in it, and we have a th400 that we wanna put in it, can we just put the th400 in with no mods or do we have to change the cross member and/or driveshaft, it has a one piece drive shaft

[VileZambonie]

That all depends on the tailshaft length. Too many variables so just measure it.

[gold84gmc]

if they are different, can we swap the one from the th350 on to the th400?

[zieg85]

Is the 4.3L and V-8 or V-6?

[gold84gmc]

what?

[bigchevyc30]

hes asking is your motor a v-6 or a v-8

[gold84gmc]

267 v8

[WilliamBos]

Is the 4.3L and V-8 or V-6?

The 4.3 is 262.

Measure the trans, you may need a shorter drive shaft.

[zieg85]

Is the 4.3L and V-8 or V-6?

The 4.3 is 262.

Measure the trans, you may need a shorter drive shaft.

Yes and the 267 is also considered a 4.3L.  I only asked the question because the frame mounts are different for the V-6...  Kick down is electric on a TH400

[WilliamBos]

Is the 4.3L and V-8 or V-6?

The 4.3 is 262.

Measure the trans, you may need a shorter drive shaft.

  Kick down is electric on a TH400

No TV cable like the TH350??

[VileZambonie]

The TH350 has a detent cable, the TH400 has a detent solenoid, the TH700R4 has a TV cable.

[gold84gmc]

if it has a solenoid shouldnt it have a plug for a connector?, the th400 we have doesnt any connectors on it

[bigchevyc30]

agreed i my truck has the th400 and i have only a vacuum hose going to it and the shifting linkage

[VileZambonie]

disagreed,

see image

[bigchevyc30]

so then whats the wire that hooks up for then and what would it do with out it hooked up cause i would like to know and on how i would wire it up. thanks for showing that vile i seem to learn something new about my truck every day