Wiring an Older MSD 8972 Timing Retard Box

[@glenbrannon7224]

Thanks for the great video and lesson!

[@jimmievaughn6923]

Will one of those old boxes work with a max five ?? I have that set up an can’t get it to pull the timing .. thanks !!

[@fastcars1173]

These older box's need to see a ground feedback from the solenoid when they are not activated. You are better off getting a digital retard as they do not need that. You can get creative with a relay that will revert back to ground when not activated, I've done that with an NOS mini and an old 7AL3 box. You have to be careful with these because if they do not have that ground feedback it will change your timing setting by whatever chip is in it, it's been awhile and I can't remember if it adds the chip amount or subtracts it. I think it adds it if I remember correctly.

[@glenbrannon7224]

Can you hook up a soft touch rev limiter up like this?

[@glenbrannon7224]

Can you hook up a soft touch rev limiter up like this?

[@fastcars1173]

Is it the 8728 soft touch with this box, 7AL-2?

[@glenbrannon7224]

@@fastcars1173 yes the box that plugs in to the 6-T box.

[@glenbrannon7224]

@@fastcars1173 7A box according to MSD

[@fastcars1173]

@@glenbrannon7224 According to the instructions, the 8728 cannot be used with an MSD box. The 7AL-2 has a rev limiter in it already. Is there a particular reason why you want the soft touch one? I've never had any issue with the built -in one.

[@fastcars1173]

@@glenbrannon7224 documents.holley.com/8728.pdf