Here is the part sheet. From looking up the items used and the set up used it is looking like it was a get the thing rebuilt so it will run and I can sell it lol. It ran decent on the test ride. Idled good at the dock and ran smooth half throttle. It was cold and quite choppy on the lake the day we took it but it was the only day in the upcoming weeks that is was not freezing and rain. It did have a little bit of a hard time on hot restarts. It would start and idle but once put in gear it would bog out and stall. He said the carb needed some adjusting as it was never Dyno tuned...

The intake and carb I'm guessing were on before the rebuild as they don't look new...

I seen many guys have oval port darts on rectangle port heads to build more torque and velocity. I've even read of some people finding stock engines with mismatched intake to head ports, rectangular intakes to oval heads. I get the oval to rectangular, but the other combo would just cause a wall for the incoming air to hit a wall, and interrupt the flow. I guess you could port match, but I really doubt the OP's engine had that done.

Yes, way back when there was no real good oval port intakes.

Also, rules racing stating OEM parts and etc.

Guys with the Ford Big Blocks ran into this too.

Since the last kazillion years though, aftmkt companies have come out with lot's of real good oval port intakes. If rules racing, GM even has a cnc 'roval' intake.

What is a easier way to see if I have the peanut ports or the rectangular? Pulling the intake or exhaust?

Pull the valve cover and check the head casting number...

Like other thread remarked it definitely was done and actually worked given the - well let's just say the right combo. I was playing with this in the late 80's even with a set of valakos completely tricked out heads with the raised floors. It was some interesting results. Much of which was on the water. I use to call it the tumble effect? perhaps creating better atomization. Who the fk knows for sure but at the time it sounded like the right thing to say. On a dual plane aluminum mag intake that was epoxied to match the heads you'd actually gain approx 100 plus rpm. Kinda found this out after the epoxy Let lose and blown out the exhaust. So ya in a nutshell I learned by accident.

It was experimenting days... For personal use only. what can I say!

But correct much improved intakes have come along since. I wouldn't recommend it however I wouldn't recommend believing your gps when it shows you to drive off a cliff but people still do it. Scratch, scratch. Makes my head hurt. Ha

Alright. Thought I read in a earlier post you have to remove the exhaust to do that. Must have misread that.

Now I know this is not by any means a for sure way of knowing but do standard 454s say 454 magnum on the top of the out drive? Just trying to give myself some hope before I dig into it hahaha

Actually, air has some magical properties. LOL. Some will build up around the mismatch (blunt side) and form a smaller , but more aerodynamically friendly shaped opening to the intake port. Thi will create a venturi and speed up the air. But again, since this makes the head port opening effectively smaller, it can limit top rpm depending on the motor. So, if the intake causes more of a restriction, then unrestricting the intake will be the bigger gain.

In simple terms, you will always make better power by dealing with the biggest restriction a motor has 1st, vs somewhere else.

On the older drives at least, the regular 454 said "7.4" on the drive and the mag said "454 Mag" but that's not a good indicator because drives can get changed. You probably have to pull the exhaust off to get to the lower valve cover nuts.

This is the way I look at it. Engine has to be removed and Intake has to be pulled to change the cam anyway, so.....let's get this party started ! LOL.

To the OP - what made you dig into this engine thing anyway ? Was it not running right ? or power down ? Or you simply got the receipt with the boat and your eyes popped out ?