That's truckin awesome , so 1700 rpm 55 mph? What size rear gears and tires?
The tires are 9.5r 16.5 and they are betwen 29-30 inches tall according to my tape measure. I've never pulled the differential cover off, but according to my brother in law (who owns a junkyard) he's 99% sure that it is 4.11.
I've got single rear wheels on it right now because the duals were in bad shape and my brother in law had these 16.5's that looked great. With the dually tires on it the RPMs were even lower because they were a slightly taller tire than these. My plan was to convert the truck to SRW, but I have a lot of irons in the fire right now so who knows how long that might be.
I did the 4l80e swap in the driveway because at the time I had no garage. I took a couple of weeks off work for vacation and did it then. Probably the most time consuming part was figuring out how to build a crossmember (which ended up being pretty easy), shortening the drive shaft (did at home with help from my brother in law), and fabricating the stand for the console shifter.
If I had to do it over again I would probably do a column shifter. I originally did the console shifter because I thought I would have to shift with it...only afterwards did I figure out I liked the light switches more.
Dan