I looked at a twinshock 420 today, engine number 560..... 85mm piston so 420 for sure, but the frame number began with 204, which sould mean 4th month 82 correct? I thought '81 was the last of the twin shock bikes? The cylinder is rooted, my next question is could I fit either an '82 twin plug 495 cylinder & head or '84 495 cylinder & head to make it a 495? I'm led to believe it could be done relatively easy and I have the option of either. Which cylinder would you use, '82 or '84? The '82 is supposed to be the most powerful while the '84 is known as the most rideable.
Cheers,
K
