I am getting ready to build a new engine for my 89 F250 and I want to use the best year of production for the EFI 460 as a base. I'm not building a race truck but I would like it to have guts. This truck is a daily driver and also a tow vehicle. I am going to stick with the SD system. I am up for some mild upgrades like some mild porting, piston upgrades, decking and such, but I do not want to compromise my current fuel economy (if you can call it that!) or driveability. If this works well, I have a 94 F250 out back that will be next. I'm going to post this over in the 87-96 Trucks forum,also. Thanks in advance for any advice.