TH350 upgrades

There is no need to interchange any components from a different transmission into a TH350 to make the transmission stronger.

A relatively basic TH350 build with decent frictions, Kevlar intermediate band, Teflon sealing rings, a heat treated intermediate sprag race, new intermediate roller clutch, new low/reverse roller clutch, properly rebuilt front pump, and TransGo shift kit will typically handle 500 flywheel horsepower in street and mild street/strip applications without any issue.

Add a 36-element intermediate sprag (requires special machining to direct drum) to the above build and a TH350 will handle 650+ flywheel horsepower depending on how it's going to be used.

Add a billet input shaft and low/reverse roller clutch support and you can throw upwards of 850 - 900 flywheel horsepower at a TH350, again, depending on how it's going to be used.

At elevated power levels it is usually a good idea (although not always necessary 100% of the time) to install a full manual valve body or transbrake valve body. The full manual and transbrake valve bodies will allow the use of slightly higher line pressure which will increase the holding ability of the clutch packs.

how much $$ for that billet input shaft and roller clutch support? Is there any benefit to building a turbo 350 at the 800 hp level over a turbo 400? thanks

EDIT: i allready have the 36 sprag and 600 hp plus spray.

prairiehotrodder said:

how much $$ for that billet input shaft and roller clutch support? Is there any benefit to building a turbo 350 at the 800 hp level over a turbo 400? thanks

EDIT: i allready have the 36 sprag and 600 hp plus spray.

Click to expand...

Part number HP3214 is our billet input shaft with custom forward drum assembly. We manufacture the input shaft out of 300M steel. We include a fresh GM forward drum assembled to the billet input shaft because we manufacture the shaft with an oversize drum spline to provide better spline engagement between the shaft and drum. As such, we broach the drum for the larger input spline so it will accept our shaft. There are no modifications required to install our shaft/drum assembly into a TH350... it's an easy "drop-in" deal. Regular price on this part number is $385.81.

Part number HP3255 is our steel low/reverse roller clutch support. This support helps prevent premature failure of the low/reverse roller clutch. Regular price on this part number is $65.25.

The TH350 features less rotating mass than the TH400, so a TH350 will consume less horsepower and torque as compared to a TH400. This means you will effectively deliver more horsepower and torque to the rear wheels with a TH350 as compared to a TH400. The TH350 is also lighter weight overall which reduces sprung mass in the vehicle. At 800 flywheel horsepower, you really can't go wrong with either transmission. The TH400 is obviously stronger, but unless you have an exceptionally high torque combination or a very, very heavy vehicle, the TH350 is a great choice for 800 flywheel horsepower when the transmission has been upgraded appropriately.

I will PM you with MR.com member pricing on those part numbers.