I asked a mechanic(so called) whats the diff. from a 2.5 and a 3.0 he said the pistons are larger and the heads are little different.. but he said the head gaskets are the same, what???? if the pistons are larger on the 3.0L would the gaskets be larger also?? and what about the valves it should be larger as well right??

 

Jaguardown, based on an 03 2.5L and 3.0L engine, this is some of the data that I was able to find:

Cylinders (bore and stroke):
2.5L engine - 81.6mm x 79.5mm
3.0L engine - 89.0mm x 79.5mm

exhaust valves:
2.5L engine - 26.15 - 25.85mm
3.0L engine - 30.15 - 29.85mm

Intake valves:
2.5L engine - 30.15 - 29.85mm
3.0L engine - 35.15 - 34.85mm

So, looking at these numbers, I would be betting that the head gaskets between the two motors are not compatable. With different bore diameters, that alone tells me that the two are not capable of being interchanged.

If you need more info, let me know.

 

well that makes sense!, i kinda new it but im no jag. expert so i thought i would ask....thanks