Right, I've got an old MK4 XR3i with 102 bhp EFI engine sitting in a shed.

What are the views on just bolting on a T3 from a std RST, plugging in an OFAC ECU and map sensor and running sensible boost (lets say 8 psi max) at a compression ratio of 9.5:1?

Would the ECU be completely off with a wrong compression ratio like that? Would it be worth to keep the increased CR and get aftermarket management or is it better to use an RST block rightaway? I've got all the parts lying here really.