Who is complaining about the performance loss ?? Build a motor with a TON of low end torque and you will not notice the gear spread as much , but then you will shorten the life of the stock OD trans .
The advantage of the Passon OD , which has gear spreads closer to that of a 727 , is you don't have to cut the car up to install it. Plus it's cheaper , price out the FULL 5 speed conversion and get back to me .