Ok so I googled the question; B18a vs B18b, and b18b head on b18a. I have found that the part numbers for the headgasket are the same for both motors. However; I'm doing a build and I have came across a killer deal on a head, which I plan on buying here shortly, but its a b18b and my block is a b18a. What I'm wondering is if I can retain the ecu that I'm currently using and just swap the parts from my current B18a head over to the b18b, like distributer, water neck, sensors, injectors, intake/exhaust manifolds?

I'm going to say yes it will all work, but I want someone with a little more knoweldge to confirm this so I'm not just hoping it will work....

 

yes, you can bolt all your b18a parts onto the b18b head and bolt it up

if your b18a is 90-91 the b18b head will flow a little better

if your b18a is a 92-93 there will be little to no difference in the performance of the two heads.

The biggest advantage you would POSSIBLY gettting out of the b18b head is a chance at a lower mileage head in better overall condition

 

the head has a pnp, stage 3 valve trains, tb cams, ext ext. But thanks for confirming it!!!