HELLO FELLOW PEG GRINDERS. I MX A STOCK FRAME 1973 XS650. I AM TOLD THAT A YAMAHA RADIAN SWINGARM WILL FIT THIS BIKE. I AM LOOKING FOR MORE RIGIDITY AND LESS WEIGHT (THE OVERSIZED MAN CARGO IS ENUF). ANY IDEAS ON THE RADIAN...IS IT LIGHTER...WHAT YEAR OF RADIAN WILL BOLT UP...ETC. THANK YOU AND...