IRONMAN

Pat were you able to run a bigger prop with the changes that you made? When I had the boat I was seeing almost 4700 on the lake at 312ft elevation M+23 prop. I think the stock motor is closer to 5000 at sea level, Hopefully Dude can chime in on that.

IRONMAN

here is one in your town, too bad it is the 375 and not the 425 allthough it says HO. I am confused.

http://www.offshoreonly.com/esvon/page-14022.html

and here is the 375 to 425 upgrade, I am not entirely sure that it is all you would need but it sounds good http://www.offshoreonly.com/esvon/page-13794.html

Pat McPherson

When I bought my boat it had a 3 blade 23p Turbo Vector.
The engine topped out at about 4400rpm with thru prop exhaust.
After speaking with JO about many possible upgrades, I ran the exhaust thru the transom and gained about 100rpm.
Then I did the engine mods.
With the same 23p Turbo the engine would spin 4800rpm. With a 23p Mirage + about 50rpm less. and with a 22p Bravo 1 about 4900rpm.
Top speed when I bought the boat was about 60 and when I sold her, 65...

Dude! Sweet!

Yup, right on or a tick over 5,000 with the Mirage 23 plus.

I haven't picked up a GPS yet, so I don't know how fast, but in 3' - 5's at 15 seconds you get one wild ride!

Oh, and that's a great find on the 496, but my wife would shoot me out of a cannon if I went out and bought a new motor for the boat right now!

tomcei

I feel ya

littledcsrodshop

iTrader: (1)

I don't know what kind of shape you motor is currently in but if all is well such as not needing the crank turned , & the cylnders are in good shape ect.. it is worth spending a few thousand on ( including the exhaust ) I spent around 3k on mine when I pulled the motor out of my 24 ( 330/TRS )
& that was including the new exhaust. My boat went from running the average 61-62 on GPS to running a solid 70 on GPS & the midrange was incredibly better , it was like getting a whole new boat. Here is what I did : ( Keep in mind I did all of the labor myself including all of the engine work so that will make a differance if you have to pay for that or will be doing that yourself. I also already had the intake , cam , lifters , & springs ( roughly another $ 450.00 or so give or take.) But if you got a good buy on some used exhaust like Kirk's you will be ahead another 1k or so from what I spent.
I give around $ 1850.00 for my headers once I got them shipped.
1979 454 330 hp / stock TRS drive
new tri-metal race bearings ( Crank & rods )
Installed ARP Wave lock rod bolts in the stock rods
New Powerforged Pistons (compression ratio approx 9.4:1 )
Z gap rings
Portwork on the existing 049 ovalport heads ( mainly bowl blending , gasket match , ect but nothing to exotic. )
Reseated valves good
Harland Sharps 1.8:1 full roller rockers
Mild Hydralic Cam ( I will be glad to give you the exact specs if you want but I would have to look them up , its been a day or 2. )
Edelbrock performer 2.0 intake
Holley 750 carb
Lightning marine headers
Of course all new quality brand gaskets
& I am shure I have forgot a thing or 2 but maybee this will give you something to keep in mind.
Like I said the boat went from running the average 61-62 GPS
to a solid 70 & was alot more fun to drive !!
I would say the motor was making a solid 450-475 HP
I was spinning a 25 pitch mercury tempest prop.

Pat McPherson

5000rpm out of a stock 330 is a bit much; you may be able to spin a bigger prop. I believe that peek power is around 4600rpm on a bone stock 330.
When I bought my 24' Super, I first powered her with a 310HP/7.4MPI. She ran faster at 4400rpm with a 26p Bravo one than spinning faster with a 24p. That engine is/was slightly different than the old carb engines though.

We all feel your pain getting approval from the wife. That's why I'm aways buying used stuff and rebuilding it...

Dude! Sweet!

Yah, my wife is still a bit sensitive from the car racing (and the insane and "inexplicable" spending that went with that). So, I think she'd have a tough time with me putting a new motor in a boat I've had for 2 months... It's just a tough sales pitch!

I've been meaning to monkey with props a bit. I think this header thing will give me a good excuse... And to get off my butt and get a GPS so I can quantify the results.

Rodshop, great info! Thanks.

littledcsrodshop

iTrader: (1)

Anytime ! let me know If I can be of any further help.

B-Stubb

Begin with the end in mind so you dont buy parts twice