Just wondering if you had the choices between these two setups for power and possible fuel mileage.

#1 Numbers 68 318 with Enginequest heads, KB167 pistons, Performer Intake; 800 Thermoquad, headers, Lunati Voodoo 60401 and .039 head gaskets matched to a low gear 904, 2k stall and 2.76 gears.

#2 74 400 block with stock heads KB240s, headers, performer intake, 800 TQ, and Lunati 60300 or 60301 cam; and not sure on the head gaskets. Stock 727 wity 2k stall and 2.76 gears.

On the street which engine would be better and get better fuel economy? I know that sounds like an oxymoron but, with gas going to 5 bucks a gallon potentially in the future. I have to ask.