Porting small block 915 j-heads

I don’t follow everything here.
220 seat (spring pressure ? )
500 + ( cam lift ? )
open ?
endurance ? Isn’t that the same as wear?
I can take a picture of my “arsenal” if you want. Have to wait till tomorrow tho.
Valves springs and everything were shipped today from US. Must have them home before new guides after that grinding begins
Springs, in regards to paper thin guide bosses, varies though..
..but eh... don't worry about it.
None of that pertains to you porting your heads which is the point of this thread.



Say, anyone seen rumble lately?