I had this idea for building a 1971 914 with a Subaru STI V2 motor. Have the car, motor and a Subaru trans. Also have 2 more donor cars.

The main car was hit in the Driver side front and had been repaired. Looks ok but will redo some of it. Inner fender was overlapped. I will cut and reweld. The others are rusty but some good parts.

Here is my question, do a 914 GT replica or just leave it stock bodied ?

You can roll the rear fenders and fit 225s. A 200 treadwear tire will usually hold the HP/torque. This is what I have on my 190hp/205tq Nissan swap. I'll let you know next month if it's enough tire with the 270/270 upgrade.
I know a 300hp Chevy swap needs flares for the tires to manage the TQ. But even then the factory flares only fit 245-265 depending on offset.