im pretty sure you can't use the pistons from the 3.8. even though the bore is the same size...

 

They're talking about a rebuild kit with overbored pistons, not just a crank swap. If I were gonna go through all the work of puting in the cank, I'd just do the whole rotating assembly.

 

Ryan doesn't know what hes talking about lol...

The pistons aren't the same.

 

Also FYI, you'll need the 01-04 oil pan. The older oil pans are different, and the crank will hit/tear through them.

 

I was going to post that but I noticed he had the correct year(s).

 

How can the pistons be any different if the displacement is only in the stroke, and not in the bore?????

The 3.8 has variations, not the 4.2, and since you're using the 3.8 block and pistons, then why would they have to be changed? The wrist pin locations aren't any different, at least as far as I can tell. I have yet to slap a mic on them though.

 

Try it for us let us know what happens...

 

From what i've read, the 4.2 pistons are shorter. It is my understanding that if you use 3.8 pistons with a 4.2 crank, the increase stroke while using same height pistons will result in them crashing into the cylinder head...

 

ehhh, I need to go pick up that 4.2 before it's gone so I can play with it. I never have got my hands on some 4.2 technical info to make sure. I'm also on very little sleep this week, so any arguements I make, are possibly complete bs lol

 

Uh oh, the 4.2L pistons are shorter.... stir stir stir....