CTC-4 Voltage Problem

All caps have been replaced and I've bypassed the selenium rectifiers w/a pair of silicon diodes. I've got 23K+ high voltage--at the lowest setting--and the plate in the horiz output tube is going red at 110V line voltage. Hmmmm. Could the higher efficiency of the new diodes be the cause here? I'm getting 350+V at pin 1 of the HO tube where the schematic says it should be about 150V. The 10W 11,000 ohm resistor and 56 ohm resistor just ahead of the tube both test OK. That, plus the HV being at the recommended voltage at the lowest setting makes me think I've got too much B+ going in somewhere. Think I need to put a 10W resistor in series just after the rectifiers? Your suggestions welcome!
Thanks,
Michael