Turbo 350 overhaul

[BigCountry]

Tomorrow I'm going to remove the worn out turbo 350 from my Scottsdale and give it to a local shop to rebuild. They've offered to do custom work to it since it will be in a big truck that gets man handled a lot.. So just wondering what are the main things you guys change or upgrade in the turbo 350's to make them stronger? Basic info on the application: 1980 Scottsdale 4x4 with vortec 350 4" lift on 33's daily driver will soon be 8" on biggest tires I can fit and be used as secondary vehicle. Any info will be appreciated thanks

 

[HotRodPC]

Not sure how aggressive you intend to get with it, but I'd go with a Stage 1 or RV shift kit. And a hardened outer intermediate race gear. That will help the #1 weakness on a Th350. If you intended get very aggressive with it, then I'd consider getting the Intermediate Sprag Drum with Dogbone Sprag and a hardened input shaft. Just make sure you're not getting China made aftermarket parts.

 

[BigCountry]

Thanks for the info

 

[crazy4offroad]

Alto Red clutches, Kolene steels, 32 element sprag with hardened intermediate sprag race, hardened input and output shafts, Kevlar band, double up the sun gear bushings but remember to re-drill the oiling holes, set up dual feed of the direct drum either internally or through a shift kit, and you can get a little more punch out of the 1-2 and 2-3 shift by drilling the 2nd and 3rd feed holes in the separator plate to 1/8" which increases the line pressure during shift. You can also do a direct clutch accumulator piston block-off mod for a harder hitting 2-3 shift but I would only do that for pure race only. Most of the stuff mentioned above would help the trans hit harder for racing and make parts last longer.

Couple of links...

Parts
http://www.transmissionpartsusa.com/350_transmission_parts_s/598.htm

Tech
http://www.crankshaftcoalition.com/wiki/T-350_rebuild_tech

Plus the MANY Sticky write-ups we have here at this forum
http://www.gmsquarebody.com/forum/forumdisplay.php?f=46

 

[BigCountry]

Awesome I intend to do anything that will make it tougher and last longer. Thanks

 

[Driver4r]

Full manual valve body. And leave out the cushion plates.
the quicker it gets into a gear, the better.

 

[HotRodPC]

Full manual valve body. And leave out the cushion plates.
the quicker it gets into a gear, the better.

I don't think he's making a Strip Only truck. For a 4x4, Stage 1 RV Shift kit is quite sufficient. Not much difference in a ..1 second and a .008 second shift. So long as you have you have firm shift instead of rolling gradual soft shift, you're good to go. I've got a Stage 1 and left out the 1-2 accumulator spring going thru a Th350/NP208 with 3.73's and still get 2nd gear chirps with 31x10.50 tires at anything above 3/4 throttle take offs, and it hits pretty hard at 1/2 throttle take offs. Pretty much an instant shift. Also don't forget, he's got a transfer case and 2 driveshafts to beat on.

 

[Driver4r]

I have a light shift kit in mine, and when i had my 4:11's i would chirp the 32's going into 2nd gear.