It's possible and been done before several times, but not straight-forward. Custom mounts are needed and you need to splice the Coupe loom into the HGT one. The exhaust will need to be adapted and you have to be creative with the boost pipes too.
I couldn't tell you exactly what needs to be done loom wise with the HGT though as I'm more of a Mk1 guy and the HGT is pretty different compared to all the other Mk1 and Mk2 Puntos.
Hassle
tbh. If it were me I'd supercharge it and settle for 160-170bhp on low boost. Or buy a Mk1 GT