Do I need HD valve springs?

[bronson@inwave.com (Nate Mellom)]

When I did the motor swap in my '84, I installed my Autotech 268 cam.  I 
checked the valve clearences, and everything checked out fine.  I 
installed my Neuspeed cam gear, and I have my timing advanced about 5 
degrees.  But I get some wierd noise while accelerating, almost like a 
chain being drug across the ground.  I've heard that a hot cam need 
heavy duty valve springs, but I still have my stock springs.  Am I doing 
anything bad to my motor, and should I upgrade to better springs?

Another question, I upgraded to the G60 rubber valve cover gasket, and I 
installed the replacement studs.  Somehow the stud closest to the cam 
gear, on the back of the head, stripped in the head (actually I think 
the head threads stripped), and I'm getting a slow oil leak down the 
back of my motor.  Any easy fix?

Thanks,
Nate
'81
'84