I think you will lose the whole essence of the RX7, the Rotary engine is what makes it unique.
Rotary engines are a lot less likely to suffer catastrophic failure than a piston engine which is why they were liked so much in the aero industry as they tend to give plenty of notice when starting to fail & get you home.
All the Ro80s that had 12as fitted hold their value whereas the V4s etc lost all their value
That is my take on it but as long as the body stays intact you can always revert back
Best of luck with it anyway & will be interested in a build thread.