280@.050, 11.5cr, and you're getting 160psi?

Sounds about right........ Maybe even a bit more than I would have expected.

My 383 @ just under 11:1, 256@.050 solid cam in at 102 would pump about 200 in 8 pumps, all plugs out, wot, battery charger on, engine warm.

My old 448 @ 9.8cr, 259@.050 roller cam in at 106, would pump about 155-160 in 8 pumps, all plugs out, etc.

I know several of the FAST guys have combos that pump 240-260.
Lots of compression and short duration cams.