I have 725 hours on my TSIO550E and run LOP and its still going strong, all
cylinders in the 60's save cyl #5 in the high 50's.  #5 was my hot cylinder
for quite a time until I put a small hole in the aluminum baffling in front
of #5 that I see Lancair is now doing in their FWF, which may explain why it
is the weakest.  A fellow 4-P pilot with the "B" engine (higher ring
pressures that caused premature cylinder failure) has over 1000 hours and
flies LOP.  My CHT's are 40 cooler LOP vs ROP.  But your speed is about 15
kts slower also as you are making less power.  I climb full rich and cruise
31" and 2300 RPM LOP with TIT's under 1650.  Up in the flight levels where I
almost always fly I have trouble keeping the CHT's under 400 ROP in the
summer.  Fuel burn is 16 LOP and in the 21 area ROP.

Larry Klaas
N51LK