I don't really have anything comparable to compare the Offy to. I've been thinking about playing around with the stock manifold though, so if I do that I'll post my findings in the write-up.

how do you know the K&N doesn't clean very well? you keep it cleaned and well oiled, yes?

what's UNI foam and where do you find it?
sizing and such?
part numbers?
photos?

so a pre-filter?
something like these offered by Summit Racing?

I was thinking this morning about having to rejet my Weber last night and increase the size of the primary main jet. all this time I've been assuming the Ramflo foam filter flows better than the the K&N, but the fact that it went lean after swapping to the K&N would indicate more air, leading me to think that the K&N flows more air than the Ramflo?