I'm debating between bolting on a GV unit on to a 727 (whenever I finally start my project), or using an A-518. I know the A-518 has a lock up converter so it drops the RPM's even more. But, the GV unit on the 727 is almost like having 6 gears, vs 3+OD on the 518. I'd like if I could have the best of both worlds and maybe use a GV on the A-518? Then I could have both lock-up and overdrive. Which of these options would be best for both driveability, efficiency and performance? Are there any better options I'm not aware of?
Also, how does the OD in the GV unit work? Is it automatic or do I have to hit some button to go into OD in each gear?