You'll change the whole B20 to your car? Why don't you change your B16A block to B20 block?If you want to be safe then sleeve the block. I have B16A 1st gen with B20 block ( I think is the one lower compression around 8.8:1).I mill the head 0.75mm. Pretty much change the i/h/e and ignition and coil,also crower stage 1 camshaft. I think already quite fast on my 2200lbs car.Once I try race with my Nissan 350Z (matic with 20" rims) on 201 meter I'll beat by around 1.5 car lenght. And one more thing,I don't think B20B intake manifold will fit cause I'll be to high.