MSD, HEI, or OEM?

Better yet just use lock out timing and run a 3,000 or more stall and loose gears. Motor will idle the best with 35 degree timing. I'm using msd E-curve dist and the lock out timing curve set up.Have a msd 7 al box and matching hvc coil to fire the plugs.

Yes these carb engines need a hotter spark since the fuel is for F.I. mist now.

Why running stock isn't so hot, if you had 1975 fuel ok, if not get the hottest spark you can afford keeping in mind the wires have to handle the spark. Sleeves might be needed over the spark wires to help cut down on crossfire and shorting to ground.

If you just slap a msd 8 box and hvc coil on most any wires 5 years old or more, LOL

The 5 and 7 wires need to be as far apart as poss