Hi, new to this forum and I just wanted to add to this thread that I have viewed many times. I was a Honda dealership mechanic for 26+ years and always a v4 nut. I acquired an '01 vfr800 motor and chassis some years ago with the intent of swapping into a gen 6 frame or building a racebike. It sat on the back burner until last fall when I purchased a nice 04 with a blown motor in Seattle. and after reading various threads on the swap, I got started. There is NO modification needed to the engine or chassis, it bolts right in with no issues. I used the 01 wiring harness and ECM with the 04 fuel injection rack and a power Commander 3 PC. Wiring and relocating the ECM to under the seat were the biggest challenges, but not that difficult. The 04 gauges were pretty straight forward to wire to the 01 harness. Delkevic header for an 04 fits the 01 motor perfectly, and mates up to the 04 Two Brothers system that was on the bike. Mounts for the 01 coils were easily fabricated, space not an issue. Deleting the ABS and delinking the brakes created extra space, especially under the seat. Can post pics if anyone is interested. Thanks for the great forum!