[RichardJ]

Don't confuse the ignition circuit with the starter circuit. You've made a number of changes at one time already, so don't introduce a new variable until you have found the existing problem.
With all they changed, I'd first check to see if they removed the engine electrical grounds. The engine must be grounded to the frame and from the frame back to the battery Neg post
Check electrical connection at the junction block on the fender. Check connections for damage and corrosion on the wires going into the bulkhead connector and back out.