It's been done before, but not by me. A quick search turns up these. There are probably more.
Running Larger Tubes in SSE (KT120, KT150)
Kt150 simple se
Calculating SSE for KT88 and KT120
KT120 in basic SSE
kt120
kt120
Running Larger Tubes in SSE (KT120, KT150)
Kt150 simple se
Calculating SSE for KT88 and KT120
KT120 in basic SSE
kt120
kt120