I thought I might add my 2 cents worth here at 5' 13" 240lbs and I've never been accused of being narrow!
Driving an ERA with the seat tracks and no mods to the pedals, and I still have room to move the seat back. I do sit tall in the saddle, but it is comfortable and after a few miles I tend to slide down in the seat a bit.
I hadn't turnad a wrench in 40 years and I put mine together. If the part didn't fit, I was installing it wrong. First few miles I was definitely scared to death that it would fall apart around me, but it's still together and mostly running. No spark at the moment, but I wired it,so I can trace it and whatever you buy the support is always available and then the wiseguys on here will bend over backwards to help.
Just do it and have some fun.