LT1 Optispark/timing issues

[paul67]

You posted earlier that 2and 4 sparked then the rest did not when testing then they did,you then say it sometimes catches which might be 2 and 4 trying to fire.I think I was the 1 that recommended the opti,bought the third 1 off him,as it was corroded my fault for not running the engine,as posted.Have you an alram fitted or an aftermarket wiring.