My Durango has the 318 and its got 173000 miles and i would like to bore out the cylinders .030 and since it is a computer controled engine would i need to do any mods to the computer or since i would only be adding another 5 cubic inches it wouldnt really make a difference in the air/fuel ratio? has anyone done this on their D, if so i would love some advice.

 

If all you are doing is boring the motor out .030 over you will have to do absolutly nothing to the injectors or PCM.

I would have the heads polished or at least smoothed personally. Have the heads checked and machined. You could also install a RV cam (or slightly larger camshaft) and you will be just fine. Install a new timing chain and gear set. Install a new oil pump! With all of this you should still be just fine with normal programing and injectors.

 

thats what i was thinking. i have an auto shop at my school and im doing the heads there and replacing everything in the valvetrain except the valves and rocker arms. would comp cams be the best place for the new cam? would i need new cam and crank bearings too? what would you recomend i put in for the cam as far as size? i was thinking along the lines of a 258/ intake/264 exhaust or 260 intake/264 exhaust since the stock is 251/252. and what would be the highest lift i could have?

 

If you rebuild a motor then you install new crank bearings.

The cam have tappets.