Valve springs...

Use the 901's with the exsisting retainers and locks if there are no signs of wear. The shims are for setting up intalled height. Get yourself an installed height spring checking tool from Summit. They're under $40 IIRC. Set the springs up to Comp's specs, then use a solid lifter (I'm assuming you're using hydraulics) and the correct pushrod (I made an adjustable pushrod just for this) and check for spring bind clearance. If everything is OK to this point, check your retainer to valve guide seal clearance.

I know you're under pressure to get this done, but do it right the first time and avoid engine damage and poor performance. Cruise and Wheel with confidence!
:burnout: