This is for any of you lucky enough to have an LT1 formie with the infamous optispark. Those E4 torx bolts in the distributor cap can be a real pita to remove. It's seems to be a bigger pita finding a deep E4 torx socket. What I did to get around this worked very well. If you remove one of the bolts on top of the throttle body, wrap it with a small piece of beer can (a good supply of beer is always necessary when working on the opti) then clamp the bolt in a tap handle. Viola!! You have an E4 removal tool. Just make sure you have enough of the bolt sticking out of the tap handle to get to the recessed bolts in the distributor cap. The aluminum keeps the tap handle from damaging the bolt too.