I have a 98s10 extended cab. It has a vortec 4.3 in it. 5Speed Manual tranny behind it. Drive shaft has carrier bearing. What I would like to do is convert it to a th350/400 tranny. But the oilpan bolts to the bottom of the bellhousing on the stick tranny thats in it. (laying on the ground with an exploded tailshaft:whine: ) So questions are for a guy that's done it:

1) Will it work? Does it hurt the motor to not have a tranny bolted to the bottom of the oilpan?

2) If it will work, what flywheel to use? Not sure if there are diff flywheel for the v6 with automatics. Not sure if bolt holes will line up.

3)Not sure if it will mess up abs?

4) Not sure if the crossmember will work. (anyone have the length of the th350ls(longshaft) and ss(shortshaft)

5) Not sure of driveshaft length.

The rest I think I can deal with .,... kick-down cable, speed-o tranny lines/cooler.

Physically hooking it up should not be a problem. Depending on the model tranny you go with, you;ll be looking at drive shaft mods probably. a T400 uses a differetnt yoke from the T350. I think the T350 uses the same as the manual.

You'll need a new flex plate to replace your flywheel.
Not sure about the bolting to the oil pan. I never noticed that. But the tranny should be a direct bolt in swap.

Issues...the computer. You'll probably need it redone. Not sure how that would work exactly, but you'll need to tie into the tranny somehow or bypass that in the computer. It shouldn't effect your ABS, but then you are talking computer again.

Pre-installtion measurements Bellhousing to tranny mount is about 21" on the th350, 24" on the muncie I took out. To tail shaft measures about the same (hard to measure in the place they are in) :P So far so good... more to come when I get the tranny in and find out what problems will occure with the kickdown, getting a speed-o and possible gearing problems.

Anyone know what the drive ratio is on a th350? This tranny I believe came out of a police interceptor but we are not sure which one of the 2 on the shelf was that one.

This may help
http://myweb.cableone.net/wpalfrey/Stats/gm%20trans%20ratios.jpg

yup thats what figured :P I'l eventually have to switch this out to a 700r4 But for now it will work. I just need to find the right crossmember for it now as the one that is in it is about 4 in' off

Woot all done... except speed-o!!! $382 later the truck is alive!!! BTW $25 to have a guy weld a 4' wide 2.5"long piece of channel iron to the xmember. It seems I need to get a sensor that changes the gear type speedo to electronic pulse. Now to figure out what I have to do to make the speed-o accurate.

Ok!!!! So here it is. If you put a th350 into a vehicle that uses VSS to the pcm this is what you need to keep that speedo, abs, and engine right! http://jagsthatrun.com/V8-chapters/V8-tpi-Speed-Sensors.pdf

$75 for the rear-end mounted reluctor gear and use the old sensor out of your tranny (if yours uses a threaded sensor). Installation looks simple and I will tell you how it works when I get the parts/have it done........:metal: