Ok I can see wanting to go with a small block but why go about it the hard way. Go to your local junk yard or Craigslist and get yourself and older 360 engine and here's a very simple low rpm combo.
.030 over app 11.0- 11.4 comp flat-tops.
nice set of H-beem rods (I used K1's)
polish or cut stock 360 crank
Balance the assembly.
Edelbrock heads. mildly ported
victor 340 intake, gasket matched
750 holly carb ( I used a 1" open spacer )
520 lift Racer Brown cam
1 7/8 Headmen headers
I used a 7 Qt. Milidon oil pan
This combo ran 10.20's in my 2550 pound Duster using 93 octain pumpgas and shifting at 6400 rpm. These heads like I said were ported but VERY mildly. I would guess its in the 450 hp range. Do yourself a favor and scrap the 318.