I'm using the Comp Cams extreme marine 278 cam and kit in my 460.  Flat top pistons, 95cc edelbrock heads, edelbrock air gap intake and 850 holley, mallory distributor, accel super coil and  MSD 6AL box. Comp cams pro magnum roller rockers and elite pushrods.  Topped that off with a stud girdle to hold it all together.

It can pull 5100 rpms with my 23 foot Glastron Carlson Berkeley 12JE and A impeller.  I think there is still more there but I haven't pushed it.  It's still to young for that.

The speedo shows 63 mph but who knows what it really is, it was near dead on at 56 but I haven't taken my gps out since we fixed the oil pan issue.

It has a nice lope but still idles down nicely, it pulls very hard.

Did you go to compcams.com and use their cam selector soft ware?   You plug in your carb size compression, valve size etc and it pops up cam grinds and HP and torque graphs.

The subject says it all here.  Which is better?   Hardin or Harmon long bolt marine logs
and snails?
Do you know of any web site that has log information?

My exits are 3" with these I'd be looking at changing the exit tips correct?

Right now I'm running Hardin short bolt logs and snails.   The port match up sucks, we ported them out as best we could but I hear the long bolt logs line up right.

I have a set of upward manifolds I could trade or what do you want for a set?   The short bolt logs and snails would also be available for sale or trade.

What do you guys have?

I would keep looking for vacuum leaks,  if you can't idle down past 1100 rpms you need to fix that first.
If it has a vacuum leak you aren't going to tune anything.   Did you try the spraying trick to find leaks?

3/8 line, Holley high output mechanical pump, no regulator.

We'll be going out tomorrow, I'll let you know how it does.

The 850 didn't do much the first time out.   I just put on the 50cc pump and bolted it down.
I got about 50 rpm's more from it if that.

Back in the garage I pulled the carb to check the insides,  72's in the front with a 45 power valve and 74's in the back.  I couldn't see a number on the rear power valve.  It had the pink secondary spring, I changed that to the long yellow. (second lightest)

I put  74's in the front and 78's in the back, this is a vacuum secondary dual power valve carb by the way.   I picked up about 100 rpms.  The plugs are still pretty light.

I now have  76's in the front and 80's in the rear with a 5.5 power valve up front.   

We'll see how this works Monday.   I'm impressed with the way the carb responds to the changes so far. 

Do any of you have the vacuum secondary 850?   How is yours set up?   I went with the vacuum secondaries to save some fuel in cruise mode.  I've used them for about 30 years on this boat.

The 850 will be on the way tomorrow,  what jets do you run?  Do you think 74 in the main and 76 in the back would be ok to start?
Thank you!

Just wondering if you found the problem?

The carb is still stock other than the secondary spring and 50cc acc. pump.  The plugs are on the  bone white side.  The mains are 70's  I plan on putting in 74's for a trial.

I didn't want to cut the carb up because I may be selling it.

I bought a set of jets off Jegs today, 70-80 for $14.99.  I have gaskets so maybe I'll
high tech next time.  I'll save the money for gassssss.

The pan is the source of many an oil pressure issue around 4300+ RPM's in the 460.  The crank windage sucks the oil from the pan and the pickup sucks air.  (theory)  The bottom line is with 10 quarts of oil in the pan it looses oil pressure at or above 43-4600 RPM's  Mine dropped from 74 to about 20 lbs of oil pressure which is where I immediately backed off the throttle.

 Milodon knows there is a problem and is standing behind the product.   Give them a call and see if they will buy it back from you as they did for a couple of us on the post.

Go to forum, engine mechanical and electrical, that's where the post is.  Check out the pictures and info.   There is an older post that contains the start and details about the issue.  It's probably on page 3 or 4 by now.   Read the posts, there is a lot of info there from a lot of people.

  It has the same heading, I just started a new post to close it as the other one was getting sooo long.