630cc - Buick Grand National/Regal T-Type 1984-87, GMC Syclone 4.3 1991-93

My Syclone idles noticeably smoother with these 630cc matched injectors, and the set came perfectly flow-matched right out of the box. Took about an hour to swap, and the difference in throttle response is night and day.

Swapped these into my 84 Grand National last weekend and the idle smoothed out immediately. The 630cc flow rate is spot on for my mild build, and all six matched within 1% out of the box.

Put these in my Syclone last weekend and the idle smoothed out immediately—no more hesitation off the line. The 630cc flow rate is exactly what my setup needed, and they fired up without any tweaking to the tune.