Why just not just take a Third Gen Supra? They have a 3-litre inline 6 that puts out about the same amount of power. They are a little heavier then the XRT, and push about 7psi stock, but BPU will do 12-14. Most important of all they look REALLY simaliar to the XRT, check them out (specificly the '91-'92 models)
~Bryan~