Flight test report and intake leak question

My Lyc. O320-D2C idles rough on the right mag, with the
#3 cyl showing an EGT drop. The roughness clears up
above 1200 RPM or so, still on one mag. It's also
noticably smoother on just the left mag, and everything's
smooth on both mags. In flight #3 CHT runs 50 degF hotter than
the rest, as well as higher EGT, which is not unusual in RVs
(I'm told)...dunno if this is also related in my case. General
consensus around here is it's either because the engine isn't
broken in yet (10 hours STOH, all at high power so far) or an
intake leak on #3. Has anyone got any suggestions on how to
find an intake leak that don't involve standing close to a
turning propellor? Any other troubleshooting advice?
Timing checks good for both mags, BTW. Chrome cylinders,
bayonet CHT probes.

In other news, with the engine throttled back a bit for temps
and the airpseed up for cooling, flight tests are going well.
Adapted from an e-mail one of you might recognize:
165 KIAS tops so far, and that's without wheel pants and
throttled back a little to keep the CHT under control.
Stall points are done. I think I've got the only -4 with
stall warning. With the flaps down the stick shakes like
mad (+/- 1", 3-4 Hz) prior to stall and airplane shudders
hard about 1/2 knot before. The shudder isn't usable as
warning, but the stick sure is.
4g turns are awesome. My g-tolerance has faded
completely, so I'm pulling up to 4 as often as I can
to get some tolerance back before going out to 6. I've
already got the gloc box checked (not in this airplane!).
Haven't had the nerve (or a plan) to roll it yet, but
I've been to about 135 deg doing pitchbacks to keep the
speed and g up. Snuffed the engine when I pushed over to
stop it ballooning after rolling out from an overbank
yesterday. It started right up again, it was just a
little unexpected at the time. I found the seat cushion
sometime after landing. Today was more of the same...without
the unload.
Landings are much easier, but I still tend to drop it in.
The RV-4 seems really good-natured on the ground, thank goodness.

Supposed to rain tomorrow. Maintenance day!

Dave 'testy' Hyde