Until the MSD screws up, which it will, and then you will be building a new motor. Been there done that seen that. Its amazing how much damage happens to an engine when the advance goes high.

I think I made some wrong assumptions on DonMan's project. His goal was 375 H.P. and I assumed that he was working off a 330 HP block with maybe some budget restraints. If budget in no problem, go with the forged pistons, and MSD. I maintain good engineering is building something that meets your specific goals with a margin of safety. If you go to far past that safety margin, an area of componet strength that the engine will never perform in, you have done things that are not cost effective.

I wouldn`t say my goal is 375hp, I would be happy with that, but would really like to see 415hp, like a 502Mag. I AM working with some budget restraints...Her name is Cheryl.:rolleyes:

RPM, I agree with you 100%. The Merlin oval ports work miracles.
9:1 or even 8.75:1 compression ratio, a good cam, this thing will make at least 425hp. I have built many big blocks and these heads are the best I have run in this type application!

I too will agree that Merlin oval-ports are probably the best head for a big block marine application in the moderate horsepower level. But let`s take a big block designed to make less than 500 hp, aren`t these Vortec heads about as good as you can get before stepping up to aftermarket heads? I already have a nice pair of Vortecs, so I am using them regardless.
I want to run the factory style roller cam, can anyone give me a good recommendation for an aftermarket retro-fit cam? Please give the specs...
It looks like I may be running a 750 Holley instead of the 800...comments?

From the other way....Why would you want to limit rpm to just 5200? If you go with forged pistons and arp bolts, go ahead and spin it 5500. I agree with wette on the cam. I ran a 226/236 112ls on that engine, and it was great for propping at 5500 WOT. This may draw rocks, but go with at least an 800cfm and a single plane intake. Desktop dyno says that alone is worth 40hp over a dual and 750cfm. Just get a straight advance TBV module (v6 or v8) and scrap the MSD, until later. The weak spot I see later on is those little 3/8" rods. They should work fine in your app, I just think they would be one of the first failure points if you push it later on. Heck I pushed the stock cast (300hp) pistons to 600hp blown and didn't have a problem. Never spun it over 5600.

A rough check on desktop, shows ~460hp at 5500-6000rpm.

This is the hp500 cam made/available from crane, make sure you use the right springs

http://dab7.cranecams.com/SpecCard/D....asp?PN=169611

Hypers are fine, Forged for what you are building are overkill
Your estimate of 385 is about right
might see 390-395 but that is about it.
Make sure if you have some advance ground into your cam you are careful setting the timing and the upper end or what these guys said about KaBoom is going to be in your face.
My cam has 4 degrees advance ground in it, Did not know that until dyno day and they put the cam grind # in to the computer.
Jason

Has anyone ever run, or know someone that has run an Edlebrock 454(468 overbore) 540 HP @ 6000 RPM package as shown in their catalogue? It uses a cam with a 112 degree lobe centerline and I'm not sure about reversion. Any help would be appreciated.