A $150,000 #3 car w/o original motor.......
Motor w/ MFI installed: $35,000 to $40,000 installed
https://bringatrailer.com/listing/1973-porsche-911s-4/
https://bringatrailer.com/listing/1973-porsche-2-4l-s-w-mfi/
https://bringatrailer.com/listing/1971-porsche-911s-2-2/
Tires, Brakes and Suspension: $15,000
Interior, wipers & heat: $7,000 to $10,000 Installed
Electrical (lights, etc): $5,000 to $10,000
Paint: $15,000
Panels $25,000
Welding $35,000
Based on my very conservative estimate; You would need to get the car for free......