Engine is big block in E Body with aluminum heads, angle spark plugs, TTI 2 inch headers.

Have been removing and pressure testing at close and full open all valve springs plus measuring coil bind, .060 fudge factor before coil bind after full open,,,,,etc, using a bench valve spring compressor and a Comp Cams install height micrometer.

Have used air pressure, rope trick and top center for ensuring that I do not drop a valve into the abyss of a cylinder,,,could be a bad day at blackrock.

Going well, albeit a bit slow and tedious. Have already found issues that I will report on later. Enough to say for now is that I have found 2 different valve springs that had less than minimum .060 between full open and coil bind,,,one of .054 and one if memory serves(I have all numbers written down) of .050. Have corrected with Porter recommendation of .050 keeper to increase spring install height. There remains some very vexing questions for which I do not have answers however.


I am at number 6 cylinder and no access to attach air to spark plug hole, rope is very difficult,,,,and do not fully trust it. Therefore best option is to ensure piston is as close to top center as possible,,,,which incidentally i have come to prefer as my favorite technique to ensure success and not drop a valve into cylinder.

My question is this, what is the best method of ensuring the piston is at its top in the cylinder.

Can I rely that the exhaust valve is fully open? Can I rely on both valves fully closed? Both by observation of lifter position in bore. Rocker assembly of course is removed.

Is not either of these, any other suggestions,,,,I have already tried placing a screwdriver or a sods straw or tie wrap in the spark plug hole. Cylinders 2, 4, and 6 are just too tight and I am working alone, turning over engine with a socket on crank pulley from beneath the csr and keeping track of these devices is above my pay grade.

I am aware that when one piston is at too center,,,another one also is. Does anyone have a chart on this that shows the companions that are at top simultaneously? Some recently posted this, I have lost track of it

Only 12 valves left to go. By the way, the 4 so far pressure tested springs measure almost as new,,,both at initial spring install height and at full open,,,,as per Comp Cams factory specifications.