opti basics
 

Thank you for posting that.

I use to have 4 of the ST-125s but I have lost them over the last 25 year. I can not find them anymore. I think they may have stopped making them because of the open spark being a fire hazard. I use the cheap harbor freight version that are in-closed. I likes the open St-125s because you could cancel the cylinder just by ground the spark with a ground wire. If anyone know where to get the ST-125 lease post a link.

I have 2 LT1 cars and on one I found that the vacuum check valve to be be fouled.
After cleaning the check valve. I have a smother running car.