SM465 to TH400 swap

[xCaliC10x]

I think my SM465 is on its last legs. Its making some weird noises, the shifter has a ton of slop in it. I think I may be waiting on doing my motor and get the trans swap out of the way, since I was going to have to do it before the motor went in anyway. The power I plan on making with my next motor I have decided to go with a beefed up TH400. I searched but I'm having trouble finding answers on a few things.

Trans, what do I use? I found that trucks used a 9" tail shaft and cars a 4". Currently my driveshaft is a 2 piece that uses a bolt on yolk. I have found that the TH400 with the 9" tail shaft is a good 12-14" longer. Does it matter what tailshaft length I use? Would a TH350 shaft out of a wrecking yard be the same? Or should I have my 2 piece modified by a driveshaft shop. Any used shaft I would buy I would have rebuilt anyway. 

I think for certain I will have to change the cross member. Is it the same cross member between the boxes, just in a different spot? Or do I need to find one out of a truck being parted?

Kickdown. Does it use electrics or a linkage?

I have a cable speedo. I plan on eventually going to all autometer gauges.

Trans cooler lines. I can just get these out of a truck thats being parted.

Since I have a tall tunnel, I was planning on using a B&M shifter from a car, I will be checking lengths, but I would rather keep it there then the column.

Thanks guys! 

[xCaliC10x]

No replies eh? Here is what my research has found over the last few days.....

So looks like I plan on getting a built TH400 with a 34 element sprag, 1-2 shift kit with deep pan, upgraded steels and clutches.

2500 stall 11 inch converter.

Trans cooler I will order from Jegs with a fan and t-stat

Lines I will use braided hose with AN fittings.

Kickdown I will use a Lokar kit that has an actuator that bolts to the pan and uses a throttle switch.

Shifter, I do not know yet, thinking of a decent Hurst or maybe a Lokar auto that looks like a stick.

Cross member I can get from CPP.

This truck should go like stink.

Once this is done, I'm gonna back burner the motor, do Caltracs in the rear and new upper and lower tubular control arms. Might as well get it to point straight......

[Grim 82]

I'm not familiar with the TH400, but I think the kickdown uses a switch that mounts by the gas pedal.
78 Chevyrado had a thread about adjusting it a while back. I will remind you though to remove the pilot bushing from the end of the crank. I recently swapped a 700r4 into my 82 K10, and I don't miss that SM465 one bit. Good luck on the swap, I'm sure you will be pleased with the results.