ok, with gas as high as outer space. and running a big block 455 with 3;73 posi. im still thinking an over drive is good money down the road. im running the stock 400 trany but thinking about the gear vendors over and under drive unit that bolts on in place of the tail shaft cone. was wondering what everyone else here is useing or have tried? tator62

 

In my vista (461 with a 3.73) I am using a 700R4 with a low stall lock up converter. I ran a pressure switch off the overdrive servo cover to trigger the lock up and also use a manual switch to eliminate any unwanted converter lock up. By the way the adapter plate works fine on going to the chevy bell bolt pattern . The overdrive ratio is an 0.70 to 1 (over a 30% RPM drop !!!! )

 

You would have to change the transmission you have now to a 4 wheeldrive type trans. The overdrive bolts on where the transfer case would bolt on. It can also go on some of the short shaft trannys but not any of the long tailshaft models as the tailshaft itself is to long. The only other overdrive out there was the US Gear and it is no longer being made. It is the old Doug Nash unit. Hope this helps a little.

 

are you sure about that? i thought all that the standard GM short tail trans would work. you replace the tail cone with the over drive unit from Gear vendors and cut your drive shaft. my understanding was that some of the corvetts came with this.

 

I work right by Gear Vendors and everyone I have ever talked to about their product has had only good things to say. I know they are more than happy to answer any of your questions if you call them directly.

Chris

 

You are correct that the short shaft is the one to use. As far as I know the 4x4 units are the short shaft units.

gene

 

If you use the search option you can read through threads on the 700R4 and the 200R4. Most people have swapped out the transmission for one of these units. The Buick guys have figured out how to build the 200R4 very strong and I believe the overdrive is 0.67 which would be significant. John

 

I've heard lots of good from these guys as well. http://www.bowtieoverdrives.com/index.shtml