Hromee Engine Air Valve Holder and Cylinder Leakage Testing Assistant Tool with M12 or M14 Thread for GM Chevy LS1 LS3 LS6

I used this on a small block Chevy 350 and it worked like a charm. No leaks or issues. It helped me replace my valve seals a lot quicker than the old way of doing it.

Works perfectly

Great tool.

I used this on a 2004 Chevy Suburban with the 5.8L engine. Two things, don't waste a hours trying to screw it in until you figure out that the O-ring between the large and small spark plug threads needs to be removed or you can't screw it into the spark plug. Second, make sure the piston is at TDC or the valve may still drop while using this device. I got real lucky it didn't fall all the way into the cylinder.

I used this tool to change the valve spring seals on my SBF 302 . Worked great , I recommend .

Product is as described, hose feels durable and everything was tight. Does not fit 2004-2007 Ford Triton engines with 16mm spark plugs. You can find an adapter by Lise that will fit this and works on Ford/Lincoln Triton engines. Still work keeping for the price since the first one I ordered has the 14mm and 18mm adapter that's so big it wouldn't even fit down the spark plug tube.

The gasket that seals this to the cylinder disintegrates after 2 cylinders. Leaves behind junk o-ring in the cylinder that's impossible to get out. Also, there's no way to get a wrench on this to turn it. The hex on the end is too thin and too close to the threads to be useful on my afr sbf heads (same with the promaxx heads) Tip, use an inspection camera to set the cylinder you're working on at bdc before airing up the cylinder as it'll turn the engine over and scare the toot right out of you

If using the M14 you must remove the M12 o-ring. Worked just fine.