Have a question about engine change. I have a 99 ext cab with the 4.2 with Gibson ext. and k&n intake. Have 3.08 rearend. and a 5sp. going to change rearend to 3.55 posi. soon.
Love the truck and will not change the engine till it is dead, but when it is I want to change to a 4.6. The truck weights to much to make much of a dif. with mods. so was wondering how much trouble to change over to a 4.6? Its my choice cuz the 5sp. should match up, a 5.4 I'm told won't.
would like to know how much trouble it would me and all the things I would need to make the change. Thanks[

https://www.f150online.com/galleries...w.cfm?num=2065[/url]

 

Wow! thats a project , Wiring harness to me would be a nightmare. The physical swap would probably go ok once the motor mounts & tranny were checked out for compatibility.
Of course you know this is going to be
$$$$ Sure you want to do this, another truck would be less hassle.
If you do it, keep us posted...

 

I know that it is going to cost some $$$ but the truck will be paid for by that time and I thought it wouldn't be to hard if I found a 4.6 truck in the wrecking yard to get engine and the wireing harness and computer. Don't know just a thought. Don't think I could use my harness I have and just get a new computer??
Any thoughts on this would be helpful. Have a lot of time to think on this 4.2 is going strong and will probaly stay together for 150,000 miles got about 58,000 on it now.