Hello. I recieved a 1974 Yamaha DOHC 500 I think. On the side cover it has DOHC 500 eight valve, the engine code is 371-109226, what model do i have TX , XS , I don't know.

I want to start restoring this bike or make a cafe racer so your help will be greatly appreciated

You have a 1974 TX500A. Search the first three digits and you will find it.

http://cyclerestorer.com/pages/show_man_serial_num.php?sort_field=4&manufacturer=Yamaha

thanks do the SR / TT / XT models interchange with the TX model, also where is the best place for parts

thanks do the SR / TT / XT models interchange with the TX model, also where is the best place for parts

I'm guessing that ebay would be your best bet for parts for this bike, or a local bike wrecker/salvage. I'm not sure if the parts will interchange between those bikes...your best bet would be to take the old part and compare it.