Thanks everyone for the input. I really appreciate your taking the time to answer my post. Some solid ideas for me to consider.
Probably will first try to resurrect my LSE Plasma III ignition system but this time use the case mounted flywheel sensor instead of the original pad mounted one that seemed to be sensitive to the heat buildup in the area of the accessories. Will also try to relocate the computer to a more forward location to keep all the leads lengths to a minimum. I've always run Bendix mags.
Already use gap seals but may change cowling openings from the 235 configuration to the 320 style. My CHT's run quite cool, so am certain there is too much cooling drag. I'm consistently getting 180-185 KTAS (dependent on temperature) at 2700 RPM (full throttle) at 7,500' & 8,500' MSL with my 150 HP O-320-E2D and Aymar-Demuth 62 X 78 propeller.
With power settings for 170 KTAS, I have a range of near 1000 NM (6.5 hours) with the 54 gallons of usable fuel at 8,500'-9,500' MSL (7 hours to dry tanks). Have on several occasions flown non-stop from San Diego to Seattle and on the way back as well (that leg was usually 5.5 - 6 hours).
When the time comes for an overhaul will consider replacing the engine with an O-360 or 390 and will switch to a CS prop at that time. This is probably what I really need to do, but my engine is still running great with very little oil consumption.
Thanks again!