[Rotary Evolution]

+1 to everything.

you want a drop in replacement for the GSL-SE without the headaches of retrofitting an FC block to the FB chassis? get a second GSL-SE fuel injected engine, simple.

and yes, if you're blowing up n/a engines all that often then you are doing something wrong.

the s4 engine should work on the GSL-SE ECU, problem is making everything bolt up, you'd have to make the block work for all the GSL-SE peripherals, which leads back to the original question as to why you would want to bother doing all that.. you'd need almost half a spare GSL-SE engine anyways. if the issue is you want the additional power from the later model engine you won't be getting it with the GSL-SE components anyways, in which case you would be better off picking up 2 FC engines, a wiring harness, ECU and all the peripherals and making those interchangeable.

if you want real power build a real engine, get a standalone, run ceramic seals and build it once without fucking with spare motors.