cruising rpm?

[Hustler]

Hey guys i was just wongering if anyone could tell what impeller i have. my boat is a 74 hustler 22.6 with full stingers i'm running a 396 that is 40 over with a mild cam and a jacuzzi pump. it cruises at 4000 to 4200 approximatly 40-45 mph and i can top it out at 5000 approximatly 50-55 mph. the boat is very comparable to the same era spectra or cambell. does any one else run these same numbers and if so what kind of impeller are you running?

[oldphart]

sounds like a loose A impeller or an AB
I have a 21 Spectra with a 460 that is mild and a B impeller tops out about 5300 RPM cruises nicely at 4500

[Hustler]

what kind of mph are you running @ 4500?

[spectras only]

Hustler,20 spectra 429 CJ , "AA" imp, stays on plane between 2900-3100RPM without trimming device,28MPH approx.45 mph= 4000RPM 4800 RPM= 60MPH

[Hustler]

sound like you have quite an increase in mph between 4000 and 4800. i guess i really need to gothru my pump and update it but every time i reach in my i cant get much further than my knuckles.

[spectras only]

Hustler,the hull designs sometimes make the difference between 3/4 and full throttle settings for speed.

[rivercrazy]

My AT-309 with an A impeller will hold plane at about 3,000 rpm. I usually cruise at 3,300-3,400 rpm at 33-36mph. It runs 45 at 4,000 rpm. Fuel economy is good as long as I don't run above 4,000 rpm. That's about where the secondaries open. Not to say I don't open em up often though!!!!

[oldphart]

4500 RPM 46-47 Mph less on glass more on chop

[Hawiian Man]

1978 Hawiian '21 Daycruiser, 460 Ford .060 over, 429 ported heads, performer RPM cam, 9.5:1 comp. forged pistons, fully balanced, Weiand Stealth manifold, Bassett injected headers, Stock Berkley 12JA pump with "A" impeller, Holley 800 Double Pump, and I get 65 MPH @ 5200 RPM wide open throttle. Cruise @ 4000 is 40 MPH.