Hey guys. I have been on the Chevy NOva forums for a while but I know a bit about the old minis too. (hopefully I will have one by the end of the week)
the company that builds the honda powered minis is called MiniTEC. you can google them. they will sell you a fully built car, or the parts to do it yourself.
A friend just put a B 16 in his 74 mini ---- insane horsepower!!!! cant even use it all because there is not enough rubber on the ground. no traction!
the MiniTEC cars are a good chunk of change and it takes a lot of work to do it yourself. If you have the time though, it is definately worth it! the most fun to drive out of all the cars iv driven!