Fullmonte77

iTrader: (3)

I tried searching but could not find. I have an 89 2.8 with the automatic. I will be swapping in a sbc and auto trans. What trans will allow me to use the stock drive shaft that is in the car now?

Aviator857

What trans do you currently have... I believe a 700R4 should work for you, if not getting a drive shaft from a v8 from 82-03 will work with the 700r4 or the 4l60E. You should be able to find one in the junkyard for cheap. But I'm like 95% sure that all thirdgens had the same.

See https://www.thirdgen.org/forums/engi...lt-do-2-a.html it seems to suggest its the same.

Your main concern will probably be the differential gear ratio.

Fullmonte77

iTrader: (3)

I have read on here that maybe a long shaft TH350 would let me use the stock shaft but not sure. I'm building an autocross car so I don't really want the overdrive tranny.

Aviator857

You can take the shaft to a driveline shop or an 18 wheeler shop and get it reworked for around $300. Compare the an autocross setup that is a drop in the bucket. Use the best tranny for the mission and get the driveshaft reworked or a new one.

Fullmonte77

iTrader: (3)

This is a low budget autocross car. Just for fun I have no intentions of being competitive at all. I have connections to UMI Motorsports that make tons of parts for these cars.

Aviator857

TH350 with the 9" (long tail housing) **SHOULD** work with stock driveshaft, but I've never personally done it.

The TH350 will cost you more in the end since you will need a trans mount that relocates the Torq arm from the trans to the mount.

Just for reference the standard gear rations in the 350 vs 700R4... personally I would want the higher ratios in 1 & 2 on a tight auto cross course, and probably the 350 for drag. but on a budget autocross you will not notice the difference.

TH350 vs 700R4
Gearing1st 2nd 3rd 4th Reverse
700R4 3.06 1.62 1.00 .70 2.29
TH350 2.52 1.52 1.00 N/A 1.92

Here is a youtube video of someone doing the swap though.

Fullmonte77

iTrader: (3)

Thanks for the info!