I want to "assemble" a low buck 400 SBC engine. It is going into my car hauler and I want to see if I can keep the price low and the fuel MPG high. Any ideas on how to build it cheaply...yet make it run good? Here is what I have to work with... To start with, I have a running, stock 1973 Impala, 400 SBC motor (block 3951511) with stock heads (3973493). I also have a 80-85, 350 4 bolt main engine that is probably worn out (judging by the loose valves in the heads). In addition to the stock 1973, 400 SBC heads, I have a set of rebuilt heads (333882) that have been completely rebuilt and have screw in studs. I also have a pair of new head gaskets. In the intake area, the 400 came with a stock cast GM 4bbl intake with an EGR valve blocked off, I have available a Weiand 8004 quadrajet intake and an Edelbrock performer manifold. Carb wise, I have a decent rebuilt quadrajet and a new AFB (600 or 650) to choose from. I also have the complete TBI injection setup off a 350 truck. The Ignition system I have is a stock HEI. The truck already has full length headers and dual exhaust. Overall truck vehicle weight is around 7000# (guessing), motor should turn 2200 rpm at 70 mph, 4:11 gears and 33" tall tires, Trans is a 700R4. Any way to assemble this mess into a good street motor that gets good MPG and yet keep the price really low? Or should I just run the 400 as a stocker? I's like to keep the price of additional parts under $300. Anyone up to the challenge???