Hi , I just bought a 90GP with 65000 miles as a daily driver till my street strip Z28 is finsihed . The car is about perfect but sinice I cant leave well enough alone I want to upgrade it some . Here are my questions . Is this a 3100 or 3.1 ? How much HP can this engine support on nitrous oxide ? Has anyone here done cams , heads or intake changes on this engine ? I found a Super Charger but its $4500 and only 80hp more . I want to change the wheels too . Anyone know what sizes will fit without problems ?