Years ago when I was still farming, I has some bridge timbers 14 inch sq. and 3 x 12 or 14 inch fir planks, used a big ass chain saw and cut a long slow slope , I used them for everything up to tractors and highway tractors. I always made sure I has stop blocks, the planks where for the cars as the bumpers would hit before the tires where to the blocks. But in a city garage that would be a bit overkill for space . I used them to chance a auto transmission on a ford ranger, front end on the ramps , back end picked up with loader and more blocks under the back end . But a word of advice, if the trans. goes in one , just sell the POS. It was the dog's and tool truck, so the Ram stays clean.
I don't see any stop blocks on those nice ones you guys built, drive off the other end is not good.
Only problem with that high was slope is quite a bit , but you could sit up under the truck.