Question on Gearvendors overdrive . Is it a basic bolt in operation for a

I hope i'm not stepping out of bounds here Jerry, but for those that don't know, he has a few physical issues he's dealing with and the manual 4spd OD idea is probably not on the table. I believe a Auto trans solution is best.
Not a problem . Hope you're doing well .
Didn't know this would go on and on . GV unit is my only choice , don't want to cut the floor , manual is out of the question . Just want a bit more mileage on the highway and less revs , my truck with the 4 speed OD revs at 3200 without the OD 22-2500 with the od , makes a big difference in noise vibration . That is all I want , only go to the track 6-10 times a year , just for fun . As it is it gets about 20-23 mpg 25 would be great, but it's the revs that get to me , what can I say getting old and cranky .
Thanks all for the info good and bad , now to make a decision , it is expensive so I don't want an expensive paper weight .