The auto is probably giving you the low hp number you've listed.
I ran a stock internals L28 built to SCCA IT specs (9 to 1 CR) with SUs. 185 hp on the engine dyno and 163 at the wheels. I know of a couple L24s built to the same IT specs with 9.5 to 1 CR and they made 208hp on the engine dyno. Again, stock internals (pistons, cam, etc.) on SUs. Just hundreds of hours in labor making sure everything was perfect inside the engine.