just installed msd blaster coil, opti-1 w/ cap and rotor and 8.5mm wires.... feels like my timing is advanced... has a rough idle and a "hobble" at lower rpms, but opens up nicely..i know the msd distributor is supposed to be set at stock timing, but it isnt right on... how do i slow the timing... just by ear? there are no marks anywhere to even tell where the distributor is set at... any help isappreciated

 

It tells in the instructions for installing the MSD opti how to adjust the timing, i think its +/- 7 degrees...not positive on that actually affcts the timing since the computer retards/advances timing also but you can "adjust" the timing on it by the screw on top of the distributor.