Will this distributor fit my slant 6?

I think you'll be happier in the long run. The drawback to Pertronix is, not everyone has parts for it in case of failure, especially in another country, so it might be a good idea to buy some replacement parts for it up front.
I also like the oe parts, the 4 pin module is cheap and small enough to keep a spare around.
was not a fan of the petronix i installed for dad, changed the timing a ton over the points.
so keeping the points in the glove box for emergencies wasn't a quick swap.