380 horse crate motors regularly dyno 380-410 on an engine dyno....
your cheapest way for getting more cam in there is to get yours reground. contact bulletcams.com about regrinding yours. I just had them regrind the roller cam in my '86 roller motor (I put magnum heads on it). I used the HR259/316 lobe on both the intake and exhaust for my 318. if you want a little rumble/higher RPM powerband, I'd probably look up to the HR273/316 lobe. about .320" lobe lift is the max you can look at without some expensive head work to get more installed height or spring travel before coil bind and seal to retainer clearance. regrind plus shipping there and back was less than $200.
to run a mechanical fuel pump you'll have to swap to an LA t-chain cover and accessory drive, and buy the camshaft snout extender from hughes.
to get springs on there that'll work with a fairly aggressive hydraulic roller lobe, you'll want to get some retainers from a couple 2.2/2.5L mopars in the junkyard and run hughes 1110 springs. you'll be limited to ~.520" valve lift before things start hitting (retainers to seals, coil bind, etc).
comp cams makes some retainers in both 7 degree and 10 degree that might work, and get you a little more installed height. they're for LS1 applications. I couldn't wait for them to get in stock at summitracing before I had to get my magnum heads together to investigate and report on them.
a cheaper (if you pull them off of junkyard heads)/ similar cost (if you buy new) alternative is GM 3100 beehive springs, they provide about .030" less coil bind clearance than the hughes springs, though. again, comp makes some retainers for LS1 applications that might gain a little additional installed height with these springs.
intake, the best options are the RPM air gap for magnums, or redrill the heads for LA intakes. I did the latter, since I couldn't use the eddie magnum air gap due to the water outlet location (offset to pass side), I didn't want to use a chinese manifold (professional product crosswind/summit intake) and I already had an LA RPM air gap. I did it on a bridgeport mill, took about an hour at a machine shop that rented shop time out at $15/hr.
