[Biscayne]

The 390 h.p. motor is already factored at 370 h.p. So not sure how much more it will be dropped. I run the 69 427 335 h.p. combo in a 69 Biscayne. I am pretty happy with this combo so far. Have only run it half a season. But so far so good. It's the same motor as a 427 390 h.p. with the 396 325 h.p. cam. If you need any help with that combo, let me know. I may be able to help you out, with suspension, motor, trans, gear, etc. Good luck with it.