small block dilema

[72hemi]

I was going to stick my 70 340 into my 72 challenger, but since I got that 70 challenger, it is going to go in that instead. SO now I have a situation. I wasnt to build a serious stroker. I have a set of x heads and I have a set of marine competition 6 pack carbs, I also have like 3 70 318 blocks. Do I use one of those and stick a 4.00 inch crank in it, or am I better off finding a 360 block, or a new 340 block from mopar? By the way I am looking to clear 500 hp, and 8k rpm.

[Chryco Psycho]

for the cost of a 360 block Why consider a 318 at all
if you have a real budget to work with I would seriously look at an R3 Mopar block stroked  which can make 700 hp range with reliability & it fixes a lot of the little issues with std LA blocks

[72hemi]

Does that block accept standard heads and intakes. Also should I use my x heads, or go with something like mopars large port aluminum commando heads?

[Chryco Psycho]

The R3 block can use std heads but if you seriously want 500 HP why limit yourself to stock heads , the R3 is really designed to use 6 bolt / cylinder heads
 The 308 truck castings ported will make 40 RwHP or 60+ gross HP more then the X head

[72hemi]

Thanks!