Distributor Connection Question

When converting from Mopar ignition to GM HEI. I discovered that the Distributor pickup wires need to be reversed.
(Ran like crap until reversing the wires) Is it OK to use Crimp Butt Splices or should that be soldered and shrink tube?
I'm have no clue how sensitive that connection from the Distributor and ECU is.
Comments/suggestions???
DKamp