Is it ALWAYS necessary to do a cpu tune after a head/cam upgrade or does it depend on how big or mild you go? For example, on a bone-stock 89 Formula 350, if I were to, as my firt mods, do aluminum Vortec heads, requisite base plate, AS&M runners, and ZZ4 spec cam (208/221?), is the pcm tune necessary right then and there or will it still run good w/o the pcm tune?

also, the fuel injectors need to be cleaned, so i can buy new ones for about the same price as having the old one's cleaned. if i were to do the aforementioned mods, plus move up to 24 lb/hr injectors (stock ones are 21, right?) would that keep it from running too lean.

i just want to hold off on the CPU tune until i get all the peripheral bolt ons as well, i.e., headers, cat-back, ORYP, CAI, GMS MAF, ect.

 

Headers / exh should have been the 1st thing you did on a L98.
If it can't get out , no point making it bigger getting in.

I ran '89 Vette L98 (113 alum head ) with similar intake mods and ZZ4 cam on stock Vette ARAP tune no probs.
But data logging showed areas when the tune could be " tweaked" for improved performance
Not recommended to change injectors without a retune to suit because it will run rich


Forget the Grantinelli MAF ; do search , most have nothing but problems with them.Waste of $$$