Floor Pan Replacement
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I picked up a set of stock vortec heads a while back, casting number 062. One of the issues with these heads are that valve lift is severly limited. The max lift in stock form is .480", but when you ad in the valve-seal to retainer clearence, you end up with a safe lift of around .450". The easiest solution to fix this is to use a set of beehive springs (26918) and retainers (787) from comp cams.
The first thing I did was remove the old valve springs. This was fairly simple with a tool used to compress the springs
Here's the comparison of the old spring to the new spring, and the old retainer to the new retainer. You can see the taper that makes it a beehive springs, and how I manage to gain a bit of lift with the new retainer.
I measured the new lift using the new retainers, and ended up with a new max lift of .555". With a .030" seal to retainer saftey clearence, I get a safe max lift of .525". Using 1.6" rockers and the XE274 cam, I will be right at that mark. You can also see a comparison of the old spring next to the new spring installed.
The installed valve height for the springs is ~1.925" on all 16 springs. The manufacturer's specification is 1.800", so I need to add shims to bring it back to manufacturer specifications.
I also converted to screw in studs. To do this, I used a tool that acts as both a spacer and a threading aid for the tap. To use it, you just set it over two studs that are next to each other.
Then install a rocker nut; in my case, I used a poly lock since it was much longer and had more threads than a standard rocker nut. Do this by hand! Using an impact might save a bit of time on some of them, but it takes way to long fix the ones that it screws up. This will take a bit of time to pull out. I had to add washers several times so that it would keep tightening and pull the stud out
Then just flip the tool so the threaded section is down. Put the poly lock on the other side (you may have to install one if you pulled them both out) and tighten the nut on top so it holds the tool in place. Then simply tap the hole. Make sure to do a good job of cleaning it up when you are done; on the vortecs, they open directly into the ports.
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