ProForm 67605 Valve Spring Compressor Tool - Heavy Duty Black Automotive Engine Repair Kit for DIY Mechanics & Professional Use - Perfect for Valve Replacement & Engine Maintenance

this tool is very effective and efficient. changed all valve springs in an hour! worth every penny.I bought this to use on my LS7, it does not fit, the bolt holes are about 1/2" too shortWorked very well doing my springs in my c5z06 with an LS6I dont usually write reviews on products, but I want to for this item.I have used the big clamp style spring tools in the past and this was much easier.The tool seems well made and made removing the springs on my LS heads really easy. I suggest using a socket addapter for your drill. Just dont over tighten if heads are aluminum.If I was to give one suggestion it would be to include some kind of little bag to put all the pieces in. Even if it adds a few dollars to the price.This thing... Is the greatest valve spring compressor ever made!!! I did both of my heads (on the work bench) in 15 minutes!!! And there wasn't springs or retainers flying all over the place. I didn't feel like I needed to wear a suit of armor while doing my valve springs with this tool lol. The only thing, not a complaint, if you are wondering, this tool does not work with Gen4 rectangle port heads. Catherdral port only! (As advertised)Spend the extra money on this tool, it’s well worth it especially if you think you’ll be doing another valve job in the future. Works great without stripping the heads or itself. Use hand tools with it and everything will work great. Try not to use power tool with it it’s not worth the time you might save. Great product!!It works as advertised, and it is easier than the jaw type. However, it doesn't work as well on the dual springs. The underside of the compressor part is lipped so the springs will compress straight, but with mine, the compressor part bottoms out on the tool before the locks can be removed. Flipped the compressor part and it works ok, but doesn't keep springs in line. Still, it is the best tool for the job if heads are still in the engine bay.Used to change valve spring on my 2002 Z06 - LS6. Worked flawlessly and was easy to set up. Would recommend.Bought a flexible air valve holder to get air into the cylinders with about 60 PSI. Worked very well.Use a magnet to quickly snatch the spring keepers when removing and a little dab of grease when installing the keepers to help them stay in place when backing the tool off.Works perfectly and being able to do two springs at once is niceTool came just as described and worked well