Abso-freaking-lutely. Time to pull that head. If it's cracked you might want to refurb another to replace it, otherwise just fix that one up and put it back into service.

Edited to add: While it's off, you might as well check spring pressures, lap the valves, that kind of thing that should always be done when a head comes off.

 

318 vs 360 vs 408........hmmmmmmm

 

alright.. i have nothing to loose.. i wont have time to do anything till next weekend... a head is much better than tearing the motor out or replacing it.. there is a place here that rebuilds heads...anything i can do to help on fuel mileage???

 

IMHO, i wouldnt put a 318 in a 2500....and it would be SOOOO much easier to just repair the head...you could do it yourself.....


and yes torque convertors would have to be changed...they are different between the two


since you just did the plenum, that will help with MPGs

 

All the normal stuff to increase efficiency. Electric fan, ceramic coated tube headers, high flow cat etc. for the lower cost mild enhancements. Turbos are nice. I think twin turbos would be cool but I bet it gets expensive.