what year dippy is it? biggest advantage, if it's an '85 or up, is that it has a factory hydraulic roller cam. if the lifters are in good shape you can reuse them, or stock replacements are $100-140/set vs. $500/set for the retrofit rollers. you can also get the stock roller cam reground by outfits like bullet cams, or trade your core in on a reground cam from hughes.
hughes sells the indy LA-X heads for less money with stock replacment valves:
la-x stock replacment or upgraded valves
la-x upgraded valves I like their #1110 springs that are installed on these. they're good to about .550" lift if set up with their recommended IH. I'm running them on some stock magnums on my 318 with a .506" lift roller cam--which was the reground stock cam, ground by bulletcams with their HR259/316 lobes for both intake and exhaust.
they also have the less expensive Enginequest heads, which have LA intake bolt pattern, but magnum rocker gear. one advantage of the magnum rocker gear, is you get the 1.6 ratio rockers stock, and aftermarket rockers are cheaper than comparable quality LA rockers.
EQ "iron ram" stock replacement EQ iron ram alloy valves EQ "iron rams" 2.02 valvesthe biggest reground roller cam I've seen offered is the
huighes 1828 which with 390 cubes should have a very nice powerband from idle to about 5500 rpm. I'd see if they can use the exhaust lobe for the intake and exhaust, making a 2828, personally, and run 1.6 rockers. Bullet Cams will probably want to see the cam before they say how big of a lobe they can get on it, but I prefer the most lift/fastest ramp you can fit. here's bullet's master list for HR cams:
http://bulletcams.com/Masters/HRlobes.htmlook at the .006" lift vs. .050" vs. .2" durations for the different profiles. while my HR259/316 lobe is 10 degrees smaller in .050 duration compared to the comp XE262 it replaced, it is only 3 degrees smaller in .2" duration (127 vs. 130) and has .008" more lobe lift.
if they can fit it on your core, for a 390, I'd use their HR272/340 lobe with 1.6 rockers, personally. the magnum based heads flow well enough on the exhaust that I personally don't think you need a split pattern cam.