I use a switch on the dash to lock my converter manually. It works good that way if you don't mind operating the switch, which I feel is no big deal. I also used a cv joint with the center section removed for a very short jack shaft. I think that is probably about as close as you can get 2 u-joints to each other. My 700r4 is out of an 87 Chevy pickup and has been beefed up with extra clutches and a Corvette servo, which makes for a very positive 1st to 2nd shift. I've been running it for about 10 years with no problems. It is behind a stock 454.