i have a 1986 throttle body EFI 3.8 . the bottom end(crank/rods) is bad . i would like to reuse the top end(heads/intake/dist/stuff). i would like to make it into a 4.2. i think a 4.2 is just a longer stroke 3.8?

1)so what year crank/ rods/ pistons can i use in my 1986-3.8 block or what 4.2 short block can i use with my 1986 top end.

2)what year 4.2 came with the roller cam?

all the 4.2 i can find have the newer multi-port EFI heads on them and they don't work with my EFI..
i'm not trying to make a drag racer but i want more bottom end torque for the stop light movement but still cruze the hiways at 75 mph here is montana. this car is 2900lbs it has 205/65/15 tires with 3.08 rear gears with a C-5 tranny. this car will be my sons as soon as he completes high school next year and with gas at $4.25 a gallon here , i don't want to put a v-8 in it or change the rear gears!

 

Take your top end and bolt it to a 4.2 short block. The 3.8 and 4.2 blocks are the same from what I understand. Everything should bolt right up. As far as the roller cam, I am not positive, but I think all 4.2's came with them, but dont hold me to it. There is a couple forum sites around that deal only with the 3.8 mustangs and 4.2 trucks, they can probably answer any questions you might have.

 

so do you know what sites? i have been looking but know one can tell me forsure what parts i can use!

 

I will pm you a place that I go to.

 

ok please resend because my pm showed-
try ******.com. They have alot of resources there to help ya out.
where is ******.com.

 

Sorry about that. If you pm me your email address I can email the website to you.

 

ok as soon as this computer lets me what i'm doing

 

I'd help if I could. I do not know enough specific details to answer your questions.
Better for me to remain silent than to offer an answer that is incorrect.

 

A 4.2 has a taller deck than a 3.8. The 3.8 intake will not fit.

 

the 3.8 and 4.2 blocks are the same for the newer years, the difference is the stroke.

 

Sorry I had the wrong info.

 

what vehicles are a 4.2 in?

 

Pickups, vans, cars, different applications - up to 2008 I think in the pickups. You could get the base XL with 4.2L 5 spd manual. The only thing was, it really didn't get better mileage than the 4.6L auto, so they dropped it. Now they have 375 HP V6 trucks.


Roller cam? I have a roller cam? I always wanted one! No wonder the engine is so quiet.