This has everything one needs to fine tune a carbureted engine. I have a very old vacuum tester / gauge and it's yellowed badly the hoses are all shot so I decided to pick this up as a replacement to tune my neighbor's Chevy Square Body with a 502bb and a Holley 850 double pumper - that morning he shut it off and I heard it dieseling real bad, said he had his 'mechanic' put a new carb on (???) and it STILL was running badly. I tuned it for him, timed it, got it leaned out a little, got his transfer slots closer to a square than they were, his timing was way advanced.. yeah. 15 minutes with this tester and a little know how and his truck fires off cold with one pump of the gas pedal and she idles at 550 (manual), and at temp shuts down without a single knock or runon.. she fires right back up warm with a half a turn of the key. Beautiful tool here!

I use two of these for synchronizing twin carburetors. At low RPM, the needles wag so bad you'd think they'd fly off their posts, but they hold true. The soft plastic cushioning around the body of the gauge prevents the gauge from getting beat up and beating up whatever it's resting on. The bent sheetmetal "hook" on the top of the gauge is sometimes handy but can be easily trimmed off with a snips if you don't like it. The fitting kit and the blowmolded case are good quality, and the inside organizer is soft enough to cut easily to customize, so it can carry two gauges instead of just one.

Worked fine with my old school 1963 Ford. Pointer was calibrated at zero, checked it against my 30 year old USA made gauge, spot on. This gauges' fuel pressure feature cannot be used on a fuel injected car as their injection pressure is way above the 10 lb. limit of this gauge. This same gauge is on Amazon, but many of those are reported way off calibration when received. Good job HF.

I assume it would work but I have to go find all the proper connections. The connectors that are included are only going to be useful if you plan on using it for small engine stuff like lawn mowers. The Lc9 5.3 is one of the most prolific engines ever made and adaptations are used in many platforms over decades. No fittings included to connect to GM fuel rails unless you cut a fuel line and push a barbed fitting in it.