Anybody here into... old Porsches?

Those were the years I was looking at too, as I read about how the earlier 2.7L engines weren't as good. How different are the Turbo cars from the "regular" 911s though? Would it work like an old Mopar where you can buy a base model and easily swap in a built-up engine and upgrade the suspension and brakes, or would it be more cost-effective to just buy a Turbo car from the start?

It's not cost effective to add a turbo. To be honest, an early turbo(930) is not a great car by todays standards. They had bad turbo lag then came on so strong they were actually a little dangerous. The owners manual warns not to fully accelerate while on a curve. You won't find a low priced turbo since even the old ones command a premium price. The turbo cars had the wide body and ran a 4spd trans instead of a 5spd due to the extra HP (also part of the driveability issue). There are lots of suspension upgrades avail for older years of 911's. The best HP upgrade is a supercharger kit at around $7000-10000. Adds 100 HP. Kev