AFR at cruise vs head temps, and an oil leak ? too Options

[agrump]

I kind of freaked this morning because my head temps this morning were at 400f on #3, 380 on #1. After awhile I remembered that the gauge is calibrated for 70f so the real temp on #3 is around 365. I am still wondering if this is too high for just cruising on the hwy at 65-70 mph. I pulled the plugs the other day and 1,2 and 4 were tan with some deposits but #3 was white with just a very light coating. Going by the receipts I got with the car my engine is a 2056 running a 280 degree cam (Fat 442), 96 "euro" pistons with TS rings. I’m not sure about the static compression ratio but I did check with a gauge and found all the cylinders to be within 112-120 psi.

I’m currently running 13.7:1 afr, should I make it richer, say 13.0:1? The car use to have carbs and the afr was around 12.0:1 but I didn’t have my head temp gauge then.

One more thing, the motor runs strong but has a mysterious oil leak, doesn't leave puddles, does show any obvious signs of burning or dripping but the oil level drops significantly every once in a while. I had the head vent hose attached to the wrong nipple on the air cleaner so it may have been pulling a vacuum; I’m not sure if moving it has worked yet. Jake warns against using TS rings so I wonder if that could be the problem.

Thanks

[DNHunt]

VDO gauge with sender under # 3 plug. Most of the time a smidge under 300.

Swap the wiring first and see if the problem follows the connector. #3 should be getting plenty of fuel supply as it is first served.

Since it was a problem with carbs. I wonder about something funny with that cylinder. Check valve adjustment, compression check, and leakdown. Or could it be a problem sealing the manifold to the head (vacuum leak). Spray a little starter fluid ner the intake and see if the engine speeds up. Have someone with a fire extinquisher handy just in case.

Dave