[1fast964]

Hey guys, after I get my car out of the body shop from a tad accident, I'm a newbie here and recently bought a 1990 911 C4, from which I sold a 700HP HKS Toyota Supra Twin Turbo for.
Well anwayze, I was doing the Service for the car; change oil, plugs, wires, valve adjustment, BUT, the mechanic told me that one of my HEAD STUD bolts broke off and was sitting in the valve cover. He showed me that the head stud was broken and where it was in the engine (the head and some of the shaft of the head stud, was broken off and theirs some of the shaft still in the block ). The head stud is broken off in the frontal area by the fan on the right corner by the muffler.
My question is, will those pose as a problem when I turbocharge or supercharge my porsche? I havent had any problems with it yet for about 1 year, no oil leaks nothing.
Lastly, what are your opinions on turbo or supercharging or should I just get the BPU (basic performance upgrades). ? Thanks for all the HELP, just wanted to do some Research before I do anything thanks!!

chris