I have a slight low rpm rough idle not bad, but I notice it. I am thinking about installing a MSD 6a box on my car. Will there be any benefit to installing it on my full bolton hot cam car with a MSD opti and MSD coil?

 

Okay, you know how on some days you car just feels like it's running really good, and then on other days it just feels like it's slogging? Adding an MSD will make it feel like it's "running really good" all the time.

Are you going to pick up much hp from adding an MSD? No.

FWIW, I'm not sure if MSD worked the bugs out, but I can recall in the past that their optisparks weren't very reliable.

If you do choose to go with the MSD 6A, go with the 6AL. There isn't a difference, other than the 6AL has padding on the back or something for mounting. When mounting, you don't want the ignition vibrating all over the place, so it's good to have a "buffer" between the mounting area and the ignition box.

 

The MSD Opti has nothing to do with a 6A box. I wouldn't judge the 6A box based on MSD's Opti issues.

The difference between the 6A and the 6AL is a rev limiter on the "AL". You can buy vibration isolators for either.

If you have a rough idle, find the problem. Don't try to Band-Aid it with an ignition box. Generally, the box isn't needed until you go to a power adder (nitrous, forced induction). There is no HP to be gained, compared to a correctly functioning stock ignition.