A 454 is always superior to any small block for tourque,maybe a stroker 383 or 400 small block is close to the same tourque,bit the big block rules--as they say,there's no replacement for displacement!.A small block probably would not get that much better gas mileage--if economy is your goal,and you still want to keep a good deal of tourque,a diesel is the motor you are looking for(but diesel fuel is now up to 2.15 a gallon here,so it might not be as economical as it was a short time ago when it was 1.69 a gallon-).
The beauty of a big block is you can put huge tires on it and still have the power to pull them down the road,even with gears on the high side(it will cook trannys though)and even when your truck is a rusted hulk,or crumpled in a ball from off roading,that 454 will still bring about 1000 bucks if its running well when you part it out--like money in the bank!.
I havent heard of sound deadening paint(unless you mean herculiner or some similar product),rubberized undercoat helps deaden noise,I've used bubble wrap plastic stuff on my floors under the jute and carpet,it made a world of difference in noise and insulation--it stays nice and toasty in the cab with it--you can also buy sound deadening pads at body supply stores--you could also get all the covering for the firewall from a diesel truck at the junkyard--my 82 diesel is pretty quiet despite the knucklecracker 6.2--if it had a gas motor I bet I would be straining to hear if it was still running at a redlight!. /forums/images/graemlins/crazy.gif
