fooling my small block

Mike,
LSA being tight really doesn't have much to do with the port velocity, but by moving the intake centerline back to the 112 that you have stated then the overlap will decrease. Which the intake valve opens and closes eariler, and by opening eariler will pull more in the cylinder, and because of it also closing eariler that the cylinder pressure will increase. Helping make poor velocity heads better performers. But you also said that you wanted sound, or lope, but this will decrease as the centerline is moved back. But the torque and HP will be stronger in the lower ranges.
The best way to change this is to use 318/302 heads on the 318 and use the cam that you want as then you will have port velocity and lope. Large port heads kill the sound of a engine unless there's a large cam installed, just as small port heads amplify the sound.
For example, my 404 ci big block engine with a .480 cam and 184 cc heads rumbled like it had a big cam in it and it was only 230 @ .050 and it had stock size valves in it. Then I put a 402 ci engine in and it had 213 cc heads and a 240 @ .050 cam with stock size valves and the sound was almost stock tame sounding even with 10* more duration @ .050 and less CI's.
The port velocity wasn't as good in the 213 heads as it was in the 184 heads and the response wasn't as good either, even though the 402 engine made more peak HP it lost TQ and I have to turn it harder. Hope this helps.