It depends on which frame you are talking about Popeye. C&J made frames from 1974 til today for an Evolution class XR 500 motor. Most of the early frames were for the Honda XL engines, both side port and centre port, but are very thin on the ground these days. So, in answer to your question, Yes, the later frames are eligible for Evo or Pre85, depending on what suspension you choose to put on the beast.
