I contacted ICE and Cleveland dizzy on the way same shaft as Windsor with the correct steel gear for my flat tappet cam, he mentioned there is a chance of spark scatter due to not having an
oil pump connected to the dist and backlash in the gears could become more of a problem as the
oil pump acts like a damper, this may only happen in 1 out of 10 and if that happens a crank trigger would be a solution. I dynoed my engine with an MSD8578 Dist and the timing was very stable.
Better to get to work and finish the interior, build a new IRS and I have an intake system to design so heaps to do before the engine makes another noise.