Goal: Mild engine with good low-midrange torque that still pulls decent to 5-5.5k and gets decent mileage. Vehicle is a K5 at about 5500 lbs, 35" tires, 4.56 gears, and 700r4. Primary use off-road so needs solid and smooth/predictable low rpm power and quick response.

Stock breather housing with large cold air snorkel.
46mm TB with unshrouded injectors.
1/4" injector spacer.
Stock small block injectors.
14-16 psi FPR
AirAid TB spacer.
Crane compu cam 2030 (Summit CRN-104221)
Roller lifters and roller tip rockers.
SR Torquer heads decked 0.020 and mildly cleaned up.
Stock ZZ4 short block. (~9:1 compression).
Stock emissions with 2.5" single exhaust.
40 series FlowMaster muffler.

I don't have much faith in the TB spacer, but the PO installed it and I see no reason to take it off.

I'm ordering stuff today to burn my own PROM, but still got lots of research to do.

Should I go vacume referenced?

I despise headers, so I'll just deal with that limit. Noise, heat, leaks, interference, ever set I ever had any experience with was nothing but trouble. And switching to something like ram horns is not an option due to emissions testing.

Opinions in general?