Trying to get enough people together to flip it over seemed like a pain and getting them back to to do it again sounded like less fun...so i did it myself.
Its hung from the rafters on one end...for some reason there are 3 trusses
right where i needed them. I tied the pitch to the horizontal beam with a sheet of 3/4 ply and bolted a 2' piece of 1.5X1/4" flat to the truss with 6" lag bots...i pulled the motor with it..never even made a noise. The other end uses the 4x12 glue lam for the door.
I spent about 9hrs time, 3 10' 4x4, some scrap 1/2 ply and 2x4 and a box of grabber screws and 6' all-thread
I had to drill 2 3/8 holes in the front of the stringers..used the bolt holes for the rails in the back....I had an issue with flex on the beam in the front.had to cheat and screw a block of wood to the bow to tie it together....4 grabber screw holes..easy fix.
I hit the line for the roll center pretty close.it rolls over by hand.
And good thing the ceiling in garage is 8'5"....if it was standard 8' i might
have had to knock out some sheet rock to get the sponsons to clear....don't want to do that..i just got done replacing all the sheet rock.