GM HEI no spark for 30 sec. when cold

[Lynn]

350 SBC with hydraulic roller and Q-Jet with 4L60E trans in my 68 El Camino.

Not resto, but definitely technical. Even with a jumper wire going directly from the batt + to the + on the distributor cap, I get no spark for the first 20 or 30 seconds (OK, maybe 15 to 20.... haven't timed it, but I am used to the cars starting right up) if the car has been sitting a day or more.

Once started and warmed up, starts in a nano second. It is NOT starving for gas. Has electric fuel pump so I can get gas to the carb without cranking.

Tried two distributors, and both did the same thing. Tried a new coil. Same thing. New pick up; same thing. New module; same thing.

Other than this, the car runs great. Got 24+ mpg on a 300 mile trip, unloaded. Pulls an 8000 pound load without any issues.

Any ideas? I have a bunch of old point style distributors, so may put one in the old Sun machine and curve it so I can try it out.