4.2 to 3.8 swap info

[fordkev]

Greetings all,

I am posting this for anyone interested in an inexpensive alternative to replacing a blown 4.2 v6.
I just completed the swap in my 98 f150 4x4 5 spd. This swap is as easy as a rebuilt long block. I used a 3.8 from a 2000 mustang 5 spd. I had to swap intakes and motor mounts, engine wiring harness etc. You have to use the 3.8 flywheel as the bolt pattern on the crank is different, remove the dowl pins and the truck pressure plate bolts right up. A couple things to watch for, if the cam sensor on the new motor is different you have to swap the whole syncronizer. I found out the hard way, swapped the sensors, syncronizer promptly wiped out the sensor, cost $60. Do not put the knock sensor in the block until the motor is in the truck, broke mine off the block, cost $100. Expensive little sucker.
Total cost of the swap, just over $800 including fluids and the parts i broke being a dumb @$$. I suspect you could do it for under $700 if you where careful with everything. Still beats $1600 for a used 4.2
Been driving it for 3 weeks, no engine light, just passed state inspection includeing OBDII test. AS for power i se a slight difference in low end torque but its more than tolereable.


hope this info helps someone

kevin

[monckywrench]

Slick swap. That engine plus a cheap F150 with a grenaded 4.2 would make an inexpensive but decent ride.

[CIRCLEBFAB]

Kevin, thanks for posting your swap as I am starting a like swap. I have a 1999 3.8 out of a mustang automatic with 49,000 miles. I am going to put it in my 1997 f-150 with a 4.2 automatic. I would appreciate any more "heads-up" you could give me. Could you tell me if you used the 3.8 injectors or the 4.2's also maybe a little more info on the cam pos. sensor. What does it take to change if I have to? THANKS!!! JIM

[monckywrench]

From what I've seen of these on Taurus engines, the cam pos sensor and synchronizer have different diameters where the sensor slides in, and some have different connectors on the sensor itself. Just use the 4.2 assembly. It removes like a distributor.

Pic of what they look like:
http://autorepair.about.com/library/...bl361a-lib.htm