I have a built ls head, i wanna put it on a b20 block for more ft/lbs.

 

im pretty sure you can. doesnt the b20 have a ls head on there to begin with. just different cams and intake manifold. correct me if i'm wrong please

 

can a b20 use the same ecu and wire harness as the ls? in a 89 ef?

 

I know the saying b-series fit all b-series?

 

yes as long as you have the right obd for your setup...ie 89 ef is an obd0 setup so use an obd ls setup for wiring ecu....very straight forward....and yes the b18a/b and b20 head are the same casting except for one head but regardless it is all interchangeable

 

you can convert to obd1/2 as well i dont mean to confuse you and say only obd0.....that is all up to you and your budget