It is a 71' 500 I bought for $250 4-5 years ago with no title. I have a 73' 750 (Stock w8000 miles but need s TLC) that has been my "go to" ride. Anyhoo, last year I was moving, and got it running to ride it to my new house, and it was like a toy, fun as hell. This winter I decided to do some mild customizing/ messing around which led to frame off rebulid, custom fabricated wiring harness,DYNA-S ignition,DYNA 5ohm coils and wires,paint-decals and endless replacement parts, rubber,switches..blah blah. I was going to put a big bore kit in it, then I discovered the SOHC4 greenspun archives. All advice pointed to a 550 motor, so I found one on eBay for $105.00 and stuck it in.
It has the Pod air cleaners, 105 jets and open headers, I also converted the rear shocks to "shorty9 3/4"struts and lowered the front fender. The tuning is a work in progress(patience right?) , but it runs welll. I cannot say enough about the DYNA ignition. I read many many threads about troubles with it. I bolted it on, statically timed it and it is ON.
I will stop blathering now....