Not anything real noticeable. Admittedly, I’m not paying a lot of attention to stuff like that lately. Big Black (name of my truck, heh heh)
Is old and tired. I figure there’s gonna be a little of that in the aging process.

I wish I would done this plenum job a long time ago. Better late than never I guess.

Are valve stem seals a big deal. Never done anything like that. If you gotta pull the heads, I ain’t going there.

 

No you have 2 options for that. You can buy a tool that you screw into where the plugs go and hook an air hose to it or turn the motor until that cylinder is on the compression stroke and shove string into the combustion chamber

 

Valve seals aren't real bad, just tedious. (as there are a LOT of them....) I have used both compressed air, (easiest) or the 'rope in the spark plug hole' method. (I use rope, as it fills the cylinder faster....) If you use rope, make sure it is COTTON rope. Not nylon, or some other synthetic fiber.... Reason being, you WILL leave debris from the rope in the cylinder. No way to avoid it. Cotton will simply burn off, and get blown out. Synthetics/Nylon are a variety of plastic. It doesn't burn, so much as melt, and can cause serious issues inside the cylinders..... You can rent the tool for the 'on the head valve spring compressor'. It just grabs the valve spring, then you screw it down far enough to get the keepers out, unscrew the tool, and it all comes apart. Just be REAL careful with the keepers. If you drop one into the engine, you have a real problem, as you can NOT just leave it in there. (if you do, you will be rebuilding your engine in the very near future......) I use a magnet to pull 'em out, lot less chance of dropping one that way.

 

I meant rope thanks for correcting that string would take a lot longer