ok i have read about stroking the 4.0 my question is that if i use the 4.2 crank and rods will they work with my 4.0 ho electronics

 

bump

 

Way more complicated than just swapping in a crank and rods but, yes, the crank and rods from a 258 will work in a 4.0.

 

but will it run on the electronics? a few years back my friend tried putting a renix motor in a ho but it would not run is why im asking about the crank because its from a older type of engine

 

anyone know?

 

youll be fine as long as you use your flywheel/flexplate so the Crank Position Sensor can do its job.

 

x2

The EMC (engine management computer) will not have any difficulty with it. The change in displacement wont bother it. Maybe it would if you went from 242 ci to 585 ci, I don't know, but the ten percent or so you get from stroking wont bother it.

Also, the 4.0 was much more modern than the 258. If you were going backwards - swapping 4.0 parts onto a 258 block, maybe you'd find some weird problem but you won't by changing the crank, rods, and other doodads. Make sure your block accomodates the accessories like alt, a/c, ps, etc.