i am personally a b-series fan, but a couple of crx w/ a z6 or a mini me give me a run for my money. i have done everything to the outside of the motor and next up is some machine work and cams. i have only heard a couple of sohc's that have an aggressive vtec sound. im getting ready to put a z6 in my hatch, but personallt i love B-series. and i have had both. you could do some mild machine work to your head as well and it would make a world of difference if you had the other parts. i used to have a y8 that was machined and i regret selling it b/c it would already be on my hatch. you can even use some oem honda pistons and rods to raise comp. but that if you are doing a full rebuild.