[slide]

I was given a 2spd auxliary transmission(20% underdrive)usgear doug nash design would this be a viable performance addition it mounts directly to the transmission could i keep this locked in for the street then shift out for freeway driving i have 3:08 gears in back ,turbo 400 with 350 horse power 350,295 50 series tires on a 1964 GMC i was thinking about changing the gear ratio to maybe 2 :74 in the rearend any input would be appreciated

[farna]

The only ones I know about fit 4x4 transfer cases. If it can be mounted behind a standard rear wheel drive trans you should be able to use it as you describe -- high rear axle then run in "underdrive" unless on the highway. I'm not real sure those things are made to run long distances at highway speeds though. Most are only used off-road, which means lower speeds for a shorter time. Try going to the Novak website. They deal a lot with Jeeps and other 4x4s, and may have some info on that particular unit. Also try Advance Adapters, I think they sell an underdrive unit.

[ericnova72]

I'm interested now Makes me wonder what kind of power these will hold, it's an excellent idea!!

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Thanks for taking the time to reply,I blew-up my 700r4 and started thinking about a turbo 400,this Doug Nash came off of my friends 66 chevy p/u it bolts right up to a t400 with 4"shaft. this is a slow project but if i go with this set up i will post the results