I jus rebuilt my 87 GTA which include 350 stock bore new pistons, crank, XR264HR-12 com cam with matching push rods and 1.6 roller rockers, slp ported runners and port matced upper and lower intake, egr and emissions delete, banks headers and full exhaust, and a superchip. Would it benfit me to up grade the injectors?if so what size? Also would i be able to tell a differance if i got a bigger throttle body? Also, im kinda stuck on what to aet the timing at? Any advice is greatly appreicated, thanks.

 

Start with the stock timing of 6, it may or may not like 8 better. The stock injectors should be fine since you apparently still have stock heads. The only upgrade I'd suggest is the Bosch III style in 24# if you want to do a custom chip and ditch that superchip in there (probably a good idea). A different TB will be of no use on that combo.