Looking for more HP from a 360

I,m looking to get more HP from my 360 with X heads.Here,s what I have..
77 360
crank is .10 over
pistons .30 over
Xheads with mild P&P
484 cam
rpm air-gap intake with holley 750v.s
stock dizzy with MSD 6al
Spitfire headers to 2 1/2 exhaust
tranny is 904,trans-go 2 kit,2500 stall
8 3/4 3.91,s

I,d like to get more HP,so do I get my heads fully done or Eddy alumi.?New bottomend?This is for my 66 Dart mostly strip,but the odd show.This winter it will be getting a minitub,spring reloc. kit and maybe a cage.Now I,ve read about 9 different builds with stock bottomend up to 500hp,so can I use this bottomend and have my X heads completely done and what cam for max.hp?Any advise will be taken in to consideration for a new engine build.Thanks

How much $$$ do you have to spend?
You will need to change the headers, go to better internals in the trans and at least 3200rpm in the converter to really see any benefiet from more engine.

I hate X heads...the exhaust port really sucks big time in those heads. "J" heads are better after porting.
Best bang for the buck is probably the RHS heads or EQ heads, unless you just want aluminum heads...then the eddy heads work great, especially with porting.