B20 > B18 for all motor PERIOD. more torque=more fun. screw people and the weak wall bs! quote me on this, A stock B20 block and head will make 280 whp all day every day, with a 60-1 turbo setup and propper tune, getting the shit kicked out of it non-stop. if your worried about walls, any walls will give you shit over 350hp anyway, so you buy a darton block or aebs block and be good for 1,000hp. if you want a fun temporary motor, go b20 with gsr,sir, or type r tranny.