i have a b16 intake manifold i just bought it came with everything but injectors and fuel rail. i know that b16 and b18 injectors have the same flow rate, so can i just put the fuel rail and injectors from my b18 onto the b16?

 

you should be able to as i believe all b-series fuel rails are interchangeable

 

Yes you can swap them over.

 

i know that b18c is interchangable but are you positive an ls will work? im thinking about buying and aftermarket fuel rail even though i dont want to spend the money. can i put the fuel pressure reg. on the b16 rail i think that a b16 is 30lb of fuel and 1.8 is 45lb will this be bad for it with the increased compression?

 

fuel rail depends on the intake manny. im not sure if you can use a gsr rail with an ls intake manny or vise versa.