I would run a real big fuse IMO. A 30 amp is fine. You could run a huge one and it'd blow upon a short to ground, and you want the coil to get all the power it can. so go with a big one.
i have heard ppl saying that when they put a small fuse in there, like a 15 amp, that the coil can't keep up with higher RPMs, and simply putting a bigger fuse in solved the problem.

odd hei question
 

When I purchaced my truck (67 lwb) The PO gave me a box of mainly useless items. One of the items was a HEI (6 cyl to fit the engine). This distributer is over sized and has the 4 pin module but does not have a coil mounted in the cap. The cap looks like a standard cap (only bigger to fit HEI). Should I use this when I do a swap and how would I wire it or should I get the more standard in cap distributer?

I'm new to the board and appreciate all of the info that I have found searching around so far.