Full stroke. That's what matters when specifying a com safe for the gas you will use. When the engine is running the pipe is pushing mixture back in when in its range. when out of range the effective compression will alter, but the power valve is moving changing that point so so called 'trapped ratio' is a moving target anyway.
If people still argue point out that foul strokes stated compression ratio never mention when the cam opens or closes the valve. Why should the position of the hole - side of bore vs top of head make a difference.
The hole in the 300 (wasn't one in my 200, haven't pulled apart a 250) helps kickstarting as it does lower the compression ratio as the engine is turning over so slowly & cycle not started yet.
Actually I hadn't read that tech article (or at least might have skimmed it many years ago). It is well written & his picture looks quite a bit like my end result, but tiny picture. He also seems to have polished the heck out of it which looks nice. I don't agree with everything he says, but not enough to argue. $75US is a very fair price to pay (about $400nz kidding, -actually our exchange rate is much better, about $95NZ) is a good deal for that existing development. Cost more in freight & time for me & I like doing things myself, but if yer stateside it would make good sense, he's not being greedy.