Personally I'd just rebuild. I mean you'd probably rebuild it twice and still have change left over compared to the price of these conversions. If it goes, rebuild it with some street porting or bridgeport, or even peripheral porting, depending on what you can live with, and a bit of work here and there and you'll easily hit the 400 or even 500 mark. Very easy to get power out of a rotary. Theres ppl running crazy power (600-700bhp) on them with out even as far as I remember touching the internals lol. Plus there will be no better sound and it keeps the balance, weight etc how its ment to be.

No offence to James, and I know its the engine he knows and reliability etc etc, but a SR20 in a RX7 makes me sick personally tbh. Sorry but just my opinion. Of your options if you had to go away from rotary power then I'd definately go the V8 route.