This to me sounds like exactly why Steve at Commercial Powertrain wants to install test/tune his own stuff before he hands it over. That to me is worth the extra time and maybe $ upfront. No one here has posted a hiccup or negative thing about his trans or work.I used H&S OD and MCC on a stock trans. Now have a Revmax 550. Tried controlling it with MCC, couldn't be made to work. Now working with a tuner using EFI Live. Will report how it goes.
I had had the Revmax for about six months now, and it has been a pain. When I received it, it had a filter that allowed excessive converter drainback. This caused the truck to lurch and surge after putting it in gear. Revmax sent me the appropriate parts, but I had to pay to have them installed in my new transmission.
Revmax's tuning, which they initially forced me to buy from a tuner, was not useable. Truck had erratic converter behavior and ridiculously low shift points. Would lug, buck, stall, chatter...etc. Revmax is not interested in remedying the situation, and I am working with a tuner to try to get it right. Hopefully it can be made to work.
My point is not to criticize Revmax, but to point out that buying an aftermarket trans is not a plug-and-play upgrade. They will sell you the hardware, but you are on your own to make it work with your truck. Trans still makes a terrible grinding sound that rattles the whole truck when it upshifts prematurely and RPMs drop under 1k under partial throttle and has to be shifted manually around town. On the upside, the trans does shift very nicely--better than the tuned stock trans--in certain situations. On highway onramps, from say 50 to 80% throttle, the thing works great.
After all the headaches and money spent, the truck is worse to drive than it was with the stock trans. Wish I had kept the stock 68 with MCC. Would have been easier and cheaper to buy rebuilt stockers if mine failed than mess with this Revmax.