I read a test in one of the mags that did indeed put one on a dyno. They got like 281 or 287 so it is more likely the bhp they are claiming is at the crank.
Those are nice numbers but that isn't what Gloveperson is asking for. He's wanting engine dyno numbers. We've already seen plenty of chassis dyno numbers.
I'm not sure any private owner would do that (but you never know!). However, some of the tuner companies would certainly pull an engine and dyno it in order to get a baseline for their products.
when i drop off my car at the k&N engineering factory they will be running my car stock on the dyno then again with the k&N air intake .. so hopefully ill have some stuff to post on here if i get the info ..
5.0 mag did one 6 months ago. They mentioned that porting was a VERY viable option on the 3 valve heads, gains were quite good, and that the engine wants more air.. Don't remember the numbers though.
I have yet to hear of anyone dyno'ng a 3V 4.6 on an engine dyno, and I doubt anyone will anytime soon. There is very little reason to, and it isn't a cheap proposition.
With few exceptions, magazines don't get cars and do that sort of thing. Rather, they find (or find out about) shops (or owners) doing something like this for whatever reason, then make a story out of it for the mag.
Flowing the heads is a whole different matter. This has been done, though I can't remember what mag it was in. If memory serves (and I do not have the numbers in front of me), the 3V heads were significantly better than the 99+ 2V heads (commonly called "PI heads" for "performance improved), and not quite as good as later 4V heads, though pretty close.
Again, I can't give you hard numbers, as I simply don't recall.