You guys with the 540s what rpm are you turning and at what compression ratio? How many hp are you getting?

5500...........9.1............630

5900, 9.5, 675

Friends 540's. 6000RPM, 9.25:1, 690HP.

Are those naturals Joe?

Let's hope mine are similar...... haha

yes...if they are the ones he told me about.

9.7 ratio 5,900 rpm 711hp

You also need to know if carbed or efi as well as if the dyno numbers are as dressed or dry headers without accessories.

I've sold the boat but:
540s from 500efis (using plenumber and mono blade TB)
9.75 cr
628 HP at 5,250 (needed more air to make more power)
699 TQ at roughly 4,300 (can't remember exactly)

The key here is these numbers were achieved pumping water in MY seawater pump, and out of MY CMI's by Mark boos at precision marine. The motors were dyno ed exactly as they sit in the boat.

Payupsucker yes they were. Dart 320 race series heads with some mild port work, bob madera solid roller, 1050 dominator carb.