Hickok Settings for Testing 6550

Hello Hickok Owners!

I'm testing a batch of 6550 Winged C's. My Hickok documentation (533) does not directly list 6550s. I have one reference that lists the following direct substitutes for 6550's: 6L6, 1614*, 1622*, 5881, 5932. My Hickok documentation has settings for all those not marked with an asterisk:

FIL=6.3, SEL JR-5347-2, BIAS=17, ENG=88, AVG=5000

However, I also have another reference that lists the following for KT88's (with a hand written note suggeesting that these settings should be used for 6550's too:

FIL=6.3, SEL JR-5347-2, BIAS=12, ENG=92, AVG=7000

Problem is, I don't know which group of settings to use. It doesn't hurt the tube to test with either group, but my mutual conductance readings in both cases are between 5000-6000. If I use the first set of criteria, the tubes read as "good", if I use the second, they read as questionable (right between good and replace).

Anybody who tests 6550's on a Hickok tester (is that you, Albert, or do you use a B&K?), please provide some clarification.

Thanks, Peter