Stumped!

[Karl Bebout]

HELP, I need somebody, not just any body....Beatles...

I've got an overheating problem that is driving me right up a wall. Never had the problem until I rebuilt the engine. I think it is being caused by a lean condition, but, its lean only on one bank. I increased all my carb jetting by three sizes and improved the overheating somewhat, but not completely. After about driving 10 miles, I'm up to 230* or more. I've installed a new 180* Fail safe thermostat, the radiator is new, running Water Wetter, have good flow, the top hose is 10-15* hotter than the bottom, I increased the total advance from 34* to 40* and initial from 16* to 20*. removed the thermostat, with no difference, I moved the tranny cooler away from the front of the radiator, I have a 3200 CFM Zirco puller fan, that is going the right way. I checked the water pump impeller and its not slipping on the shaft, I've checked all the intake manifold bolts and they are all tight. I've doused the intake/head juncture with carb cleaner, at idle, with no increase in RPMs. The plugs on the driver's side are plenty dark from the heavy jetting but all the plugs on the passenger side are very white. They did darken, just a bit, with the increased jetting, but are still not the shade of tan, I prefer. I do not have an air/fuel ratio gauge and no oxygen sensors or engine control electronics. Has anyone ever run into such a situation? I'm stumped and any advice (other than put in a Ford engine) will certainly be appreciated.