30Special

AHHHH, gotchya !!

i would say some custom weissman transmissions would work super not brake at all , no matter what power u put in.

Then u could have 2 reg LH engines instead of the counter rotating one !
But i know , its not cheap.

picklenjim

For ignition MSD 6M marine boxes. Availiable with or with out rev limiter. Since you now have 496 cu.in.'s you would need a 800 or 850 holley.
As for props there are all kinds of places on the internet but you may be better to deal with a local prop shop.

ezstriper

Its a inboard !!! got the same deal on my gibson...you got the right guy on the cams..you staying with hyd flats ? do not used a performer RPM, only std performer...you will never see the RPM you need, forget the MSD, use a H/P HEI eliminate the vacume advance and keep timing at a max 26-28 total, I run edelbrock 600's on my 454's work great never see 4k, I'd go with their 750's on this...you will be running in the 3300-3600 range most of the time I'm thinking....if more opec will yove you long time !! good luck..

fastestonehere

What intake manifold would you guys recommend.
Holley carb, which model

and why not an MSD?

30Special

I say MSD is fine and a 800 Holley would be perfect but Bob M. can tell u what u need, i would let him do a build sheet not just a cam !!!!

FIXX

Stick with the airgap,even tho you wont see 6500 rpm's its still a better intake then the performer intake...you wont be boiling the fuel from under the intake from the hot oil splashing on it.

flyinlow

The Trojans are an incredibly well built boat and of course as he is saying are either direct drive or V drive but either way have fixed prop shafts and no drives on the back of the boat
I think you are a little optomistic on the HP of the new engines but being reverse rotation doesnt cause any real problems

rrrwel

Fastestonehere I know your boat well.

I'm vey interested in what you're at doing because I'm looking to do the same thing on a 21000 lbs boat . First, do you have Crusader engines?

The reason being is You said that you have "2 454 MK IV,s one standard rotation one Reverse rotation "crank spins backwards" cam is standard direction reverse firing order "gear driven" -

Are you saying saying that your cam is a standard cam and not a reverse cam in the reverse engine? I was thinking I would have to get a special reverse grind cam on mine, but if it's standard cam that would be great.

I was hoping to use a mild cam that would utilize the added stroke to acheive about 400 to 420 hp and 500 lbs of torque in the crusing range. With our type of boats its all about torque, so any way I could acheive more of it that would be better. I also run 72c transmisions. As far as propping I deal with prop scan out of Chichago, they are excellant. With my boat I was hoping to get a couple more inches of pitch with the added torque and then cruise at a higher rpm. I use fuel flow meters and know that if I currently run at 3500 rpms I get better fuel ecoonomy than at 3200. I was hoping to run the rebuilt stroked engines at 3800 because despite the higher rpms the more the boat gets up out of the water the more efficient it becomes. Your boat with the Delta Conic hull begins to really move once it gets on top of the water.

I'm also interested to know what the cost of your rebuild is going to be.

One other thing my builder is concerned about is water reversion if I go too radical with the cam because I do idle alot when trolling. Please let me know how things are progressing and what kind of performance your're looking to get. Any suggestions are welcome.

Good luck - keep me informed

HaxbySpeed

The cam spins the standard rotation but has a different firing order. I've done a couple stroked reverse rotators they work fine. It's the only way to go unless you change trans. On V drives you can change their direction but straight shafts you're pooched. I'd use the stock GM small cap HEI, the MSD marine distributors are junk and you have no need for a box. ProSytems can build you a set of custom carbs matched to your combo for not much more then out of the box carbs and they work great. Good luck with the project.

ezstriper

you do not need or gain a thing from MSD(may soon die) you do not need the performer RPM, look at where the power band is, you do not anything over a 750 at most with this application..you want max velocity and torque..again 3500 rpm going to be where it lives...