[Elecraft] K2 Output power

[TL]

Hello all K2 users
Just finished an extensive set of MODS to # 1574 and very happy with results
(AF Pot, all filter Xtals change, ALC, Sidetone, Agc).
After carefully adjusting my K2 "by the book" I find  my output power /
current (dummy load) to be as follows:
band    power           current
80       10.3w            2.1A
40       10.0w            2.2A
20        9 w               2.3A
15        8.8w             2.4A
10        8 w               2.6A

My RX voltage / current reading is  13.6v 0.30 A, on a K2 equipped with
KIO2, KSB2,KNB2
K160M and a small AMP keying interface.

I have noticed an 0.6 V- 0.9 V  drop on TX when level is set to 6-10w ( band
dependant.).
These power reading , are from my external analog power meter and are always
lower by
0.2w to 1.5w from K2's  internal power meter indication. (worst case 28
Mhz).

I am not able to do any better after many tries on peaking the BPF's and
adjusting.

Is this a possible normal behavior ?

Any comments to clarify will be appreciated.
Thanks in advance de Isaac, 4Z4TL