yep, the 274 deal is 10.36 rounded to 10.4:1
and
the 284 Engine just slightly higher at 10.48 again rounded to 10.5:1
Stealths all seem to CC right around the 83 mark, we took them down to 80CC, then just Block Milling downfill variance.
Both run great on 91 Octane Pump Premium... No detonation, also, no difference with the 94 Octane tried on the 284 Engine, same, same, but the guy had some so we tried it... it didn't care.