It depends how good the greens are!!
If they are gummed up with varnish not as much as if they were nice and clear.
I have personally seen and been at a test session on an engine dyno with a cossie lump on greens, ie 0280 150 803's where it did 377 all day long repeatedly with no lean off at all at std fuel pressure.
My own one has just made 328.8 and nowhere near the limit on greens duty cycle.
tabetha