difference between EX and SI

Is it possible for me to put DOHC heads off of a 99 SI and put them on a 96-98 EX motor? Both are vtec motors and both are 1.6 liters. Im just wondering if there is some other critical difference between them like the computer tuning or something else. Im looking for bolt on performance that wont hinder drivability. Thanks.

They are completely different series engines. The Si is a B16A2 and the EX is a D16Y8. You can't mix/match between different series, they don't physically work together.

if you were gonna swap...youd have to do the whole engine..cant mix and match between engines

Can't head swap. SI is Dual-Over-Head-Cam (DOHC), while the EX is only Single-Over-Head-Cam (SOHC). Doesn't match up. Huge bummer. My buddy is big into saturns, and he told me they only had one block at one point for both DOHC and SOHC heads, which meant interchangeability.