My 4.2L blew a head gasket and its now worth rebuilding the engine because it has over 250,000 miles on it. I want to know if I can put a 4.9L in it and what would I have to do to do so. OR what would be the easiest and lest expensive replacement. It is a 2002 F150 Sport XL with T5 trans. everything is stock.

 

I'd put a 4.6

 

The 4.6 will not bolt to the 4.2 transmission. I would look for a good used 4.2. A 4.9 or a 5.0 would bolt to the transmission, but neither one would be an easy swap for many other reasons. In fact, I think the 4.9 is too long to fit under the hood.

 

A 2002 4.2 V6 with a T5 transmission? First I've heard of that.

 

lol OP are you serious? if you didnt swap it you either have a 4R70W or M5OD

 

I'm assuming he meant M5OD-R2.

 

anything is possible with enough skill, time, effort and money, it honestly sounds like you have none of the requirements...

 

If you are inclined to do most of the work yourself then it is feasible, but if you are going to pay a shop to do most or all of the work then no.

You would be better off just selling the truck ( parting out ) and investing in another 97-03 with a 5.4 or even the 4.6

Hell, I only gave $7,000 for my 01 4x4 5.4 scab and to me, after all is said and done you will spend that much PAYING someone to do what you are asking... regardless of what size you want to go with.

Dont get me wrong, if you are gonna turn wrenches then definitely go for a 4.9 or 5.0 like glc recommended. Just be ware of what glc said also...check all specs before hand to make sure it will fit.

 

A 302 swap would be easier than a 4.9. You can just get a stand-alone harness and ecm for that. Theres tons of aftermarket for it. You'd have to fab your own engine mounts and use all the accessories from the 5.0. Also a 5.0 flywheel.

A 302 dressed up barely fits in. I'm pretty sure a 4.9 won't fit without some major surgery to the core support to move the radiator forward more.

I wish my '97 was a manual. It would be on the road right now. If you really can do this or have someone who can physically help, give me a pm and I'll help you with what you need to do it. I'm a fellow Michigander doing a similar swap right now.

 

My bro and I r doing all the work. We have shop that we can use, were not putting a v8 in it because we would need a whole new Wiring harness. Thats a pain I don't want to do with. I wouldn't even think about putting a 5.4L in it with all the problems they have. So my best bet is probably find another 4.2L then. Thanks guys

 

What year 302 should I look for and does it have to be out of a truck or could I drop a 5.0 HO into it. My bro has a fox body with about 600 hp. It would just **** him off

 

I have 148k on my 5.4 and no problems other than an intake gasket.
Oh well, it does make things easier to go back with what was in the truck.

Good luck

 

If your going for one, find a 5.0 HO out of a car. They have a roller cam and are already set for MAF. A stand alone harness is easy to install. For a little more than $1000, you should be able to get a good used motor, harness, computer, and other small odds and ends. You wouldn't be completely replacing the trucks harness, just bypassing the parts for the old 4.2 and laying in a different one for a 5.0.

 

Over 250,000 on the 4.2 and you want a 4.9? Do yourself a favor and get another 4.2. They are more fuel efficient than those older engines. If you want more power, buy another truck.

 

Hello, I have a 2002 ford f150 lariat fx4 and the engine (5.4 triton) won't go past 3x rpm's no matter how hard I press. The tranny shifts at random times and mechanics had no clue and so I wanted to swap out the whole thing, I've got about 10,000. I was looking into getting the same engine supercharged but I need help picking the right transmission and axles, I'm looking into making it kind of a prerunner, I already got KYNG shocks and new leaf springs. With upgraded control arms and sway bars. Just need the power to get her going fast off road.