OK lets have some discussion, I been slowly gathering parts for the 92 dakota 318 auto truck and the time for much improved MPG is here, I have an a-500 to swap in place of the 518 and am preparing some heads to throw my suite of mods at but really wish I could get more compression while still keeping the flat tops.

Cylinder head mods are going to be opening the intake valve seat to match the size of the valve as the seat diameter is much smaller, then run as sharp of valve seat angles as I can get on the intake while mirror polishing the ex valve to reject heat. I have found nice gains just opening the port at the PR pinch especially on the PR side because the fuel sprays there instead of the back of the valve and opening it up allows more to hit the valve where it belongs. Also I will be running ferd yellow 4 hole infectors. Top it all off with about .030 head milling and I just might try the "singh grooves" this time.

I will zero deck the block again as I have done in the past and run a .028 head gasket but I still am only going to have just under 11 to 1... I would really like to try at least 12 to 1 and retard the cam timing to bleed off some of the compression and let the cylinder pressure work on the crank a little longer before opening the ex valve. I really don't want a dome screwing up the flame front... maybe I should build some heat stoves to suck hot air off the exhaust manifolds?

When I did this basic engine in a 1/2 ton it would not ping with nearly 11 to 1 on 87 octane, it actually seemed more octane tolerant than it did stock. It gained some MPG from that but really wanted to try more compression but could not easily figure that out... that truck benefited from slowing down the RPM by installing 265-65-20 tires (stock had 245-75-16 tires and 3.55 gears) . Recently I was going to put some 2.76s in this dakota that also has 3.55s but much shorter 235-75-15 tires but when I pulled the gears out of storage they were rusted beyond usable... I am looking for another nice 2.76 or maybe 2.94 for the 8.25.

I will not make the bed unusable so no tonneau cover. I will not switch wheels and tires as I drive on dirt roads and can't have rubberband tires getting holes in them and bending wheels.

I have thought about finding some slightly smaller injectors and unplugging the O2 to make it run leaner but I know that could be a crapshoot. I read once upon a time about a wideband A/F sensor someone sells that will send a false o2 signal signal to the computer to change the ratio to whatever you set it at, anyone know who sold such a thing? How would that work if I wanted run 16 to 1 or something at cruise but normal A/F 12.5 or so ratio at WOT?

Anything else I am missing (besides EGR, still not buying that)?