here's the deal. i own a 1999 f-150 with the 4.2 v-6 in it currently. the motor developed a knock in the block. i have a buddy with a 1997 mustang 3.8 v-6 he'll give me to use as parts. he has the motor, trans, harness, computer, and a bunch of other stuff. can a swap be done? are the blocks the same? if i wanted to keep the 4.2 head and use the 3.8 block. if someone can help me find the cheapest way to fix my truck i'd greatly appreciate it.

thanks
chris

 

I can't say for sure, but suspect a swap is "do-able". Probably more so than any other swap for a 4.2, but I don;t ever remember anyone here doing it.
Have you ahd your 4.2 inspected to find out what would be required to get it fixed and back on the road?

You mentioned finding the cheapest way to get your truck fixed.

The first place I'd start would be finding out what it would take to get the original motor going.

If you do decide to go forward with the engine swap, you might be able to get som more info here at FTE in the Engine Swap forum.
Maybe somebody there will no more details.

Thanks much and best of luck regardless of which way you go.