Can someone please tell me what can I possibly update on this engine. I already added an intake, headers, and cam gears. I don't know that much about engines so please help me out.

 

hi flow cat,and a 2 1/4 exhuast ,
and a fuel pressure regulator,
take it to a dyno and have them tune the cams
gears and fpr, that should keep you busy for now!

 

whats a fuel pressure regulator for?

 

to turn up or down the fuel pressure,in your case after you get a high flow cat and exaust
the flow of air is more and more fuel needs to be added in the mix

 

not to turn anyone away...
but...
go to preludepower.com's 3rd gen forum.

there's all sorts of homemade ingenuity over there...

personally, i've got a ported/polished head, milled 30 thousandths to up compression...
aem cam gears, putting a FPR on, custom intake, dc header, thermal exh, custom test pipe...

not too much else you could do...
get some cams and new valves/springs... or turbo it.