I am a retired engine builder (mostly stock/near-stock) to go in Street Rods for long distance running. I have rebuilt a 200 Six twice and both had this overfill problem. After running about 20 miles I checked again, and the overfill was still there. The blocks were hot-tanked, the head cleaned and the pan, oil filter and all related parts either new or rebuilt. It appears 4 quarts works fine in this little engine. My 65 Mustang is bored .060", 2-barrel adapter, Autolite 2100 286 cfm carb, ACCEL coil, Pertronix trigger in a 68 distributor (see note), 8.5 mm wires, cool-air intake, free-flowing exhaust and minor head work. Over the 4th holiday we went 2,275.5 miles getting 24.5 mpg running the AC all the way and doing 75 mph most of the time...sometime even faster in the NASCAR lane! When I topped-off the oil I got some blow-by out the oil filler. Not serious but it suggests an overfill. The suspension has been updated with poly bushings except the front struts/locaters, V8 GT springs, 15" tires, rear sway-bar, gas shocks and front disc brakes. I feel safe with 4 quarts but use oil with added zinc because newer oils removed it. Flat tappet cams need it. I am also a retired gunsmith and I am very familiar with hot moving metal parts. NOTE: The 65 used a matched carb-distributor called the Load-A-Matic system. It had a vacuum valve on the side of the 1100 one barrel carb that tied to ported vacuum to operate distributor advance. The carb MUST be the 1100 with the vacuum valve on the side of the carb body and it MUST be connected to the ported vacuum, NOT manifold vacuum. If a later distributor is used...like I did, use manifold vacuum for advance. The later dizzy uses vacuum and swing-weights to advance timing, so the vacuum valve must be sealed off and manifold vacuum used. I tried to ad a pic but unable.
