Does anyone have a electrical drawing for a test stand.Small block
with msd ignition

I think the MSD large red/black wires would go directly to the battery same as they would in the vehicle. Small red MSD trigger wire to on/off switched 12V toggle switch. Switched 12V to the coil from the same toggle switch so when you flip it the MSD & the coil are hot & ready to go. I am assuming with that last sentence that no ballast is used for the coil with MSD. Momentary contact switch for the starter solenoid small terminal. As you know large cable from batt positive post to starter big lug & large cable from batt neg post to block. EDIT I missed something & I think that is that the coil neg pri terminal goes to the MSD. I might be off here so here's a BTT & others will chime in

Coil require no wires to it other than what comes out of the MSD box. If you have extra wires there, something is usually wrong.

Just follow the instructions on how to wire the MSD.

I've got one that was already wired. I've felt that if you do various engines, that's the way to go. If you do complete car restos that are similar, it would be smarter to set it up so you use the engine harness with bulkhead connectors and the cluster or dash. That way, you also test all the wiring.