Help me add 100 hp to a magnum 5.9 on a super tight budget

You would be looking at buying heads, cam, intake, headers.

Mostly.. once you put a mech advance distributor on it... it's already gonna make 20 more. The things dont advance more than maybe 20 degrees I'm told. I should check myself.
So if it's a 240 hp motor.. it shouldn't hard to get 320 out of it with the cam,heads,headers. 90 hp or 70 after the timing is cranked up depending on how you look at it.

Or like the other say... do nothing and add a 75 or 100 shot of goofy gas