98 4.0 swap question

[payload]

I've done some searches and read some post and how to threads and I see What years they say are optimal for the 2.9 to 4.0 swap into my 91. What I have is a 98 ranger that has been rolled but the engine is unharmed it was a 5 speed manual 2wd my truck is a 91 5 speed 4x4 I know I'll have to do some more wiring since I'm swapping to a newer computer I just was wonderi g is it do able using my trans and stuff with the year gap. Thanks in advance.

 

[MarcosLopez77]

im doing almost the same swap. my truck is a 1990 2.9 4x4 and my donor is a 98 4.0 4x4

theres a few things youll have to change out.

-your oil pan from the 98 block will need to be changed to an earlier model

-your upper intake will also need to be changed (assuming your 98 has a plastic intake like mine did) the plastic one only has 1 fuel line as the older has 2

-the main thing your gonna need to swap is the entire wire harness and computer (look for 89-92 ranger harness) might not be exact on the years but a ranger harness is a lot easier than an explorer harness

-your transmission is probably fine but if that 98 has an 8.8 rear axle id swap that as well while your at it, might need to change the gearing though to match your front axle

 

[MarcosLopez77]

oh you might want to keep the exhaust manifolds and y pipe from your 2.9. the 98 has y pipe has 2 O2 sensors. that's not gonna work with your wiring either. although ive read you can plug them both and relocate 1 of them where the pipes join.

 

[payload]

I'm swapping the whole fuel system from my donor truck so I don't need to do the intake set up. My biggest problem looks like it's gonna be wiring right now.

 

[holyford86]

Ok, you can use the 98 block and oil pan, the only differerence is a lack of oil level sensor in the pan, you don't really need it anyway. The best way to go about swapping this is to get an engine wiring harness, upper intake, and all associated sensors from a 90 or 91 4.0 truck and use that. Other than a couple sensors on the 2.9 it is worthless to you, carefully unplug the fuel lines and engine harness, then hurl it in the nearest dumpster. Then install your 4.0 with its harness and sensors.