Hello 65coupe302,
Man I wish you would give me a call.
To be sure you understand - - you want to insert nylon ROPE
into the spark plug hole. I would use a rope about 3/8 inch thick.
The theory is - -the rope fills the area above the piston and when the piston moves
it pushes the rope up to hold the valve. You gotta put quite a bit of rope into the
spark plug hole. be CERTAIN the rope is long enough to hang out of the plug hole.
When you turn the motor by hand the rope will get forced up and hold the valve.
Then you MUST back the motor up to remove the rope. This is of course after
replacing the valve seal. People use compressed air to fill the cylinder but that is a little shaky if the air slips past the valves or guides etc. I think safer to use the rope just take your time.
The valve seal looks like rubber washers or boots. They are located inside the valve springs. You need to remove the rocker - - then compress the spring to remove the retainer - -then the spring will lift out of the way and you remove the old seal.
I should also mention - -you could have issues with the valve guides as well.
Trust me on this - - I can offer loads of ideas but I hope you can call me.
Here is a link to a place I use a LOT
RockAuto Parts Catalog
You should also be able to get seals at your local parts store like Pep Boys or Auto zone
Let me know what you are gonna do. I was thinking your friend was all set with this BUT I would feel better if I could be certain you know what you are getting into.
I hope he has a tool to compress the springs or you can rent one from AZ or PB's.
I NEVER want to impose on someone's project - BUT I do want to feel as though you understand the process before you start.
Hang in there - -it is NOT a bad job - Print Dad