Cast Iron intakes are stock pieces, a 540 is way bigger than any stock production engine. That means that the cast intake will not support the air needed in a bigger engine. If your engine builder did not tell you this, you might want to get a new engine builder.

I have a factory cast one. Perfect condition, rectangular ports with the brass inserts. Also fel-pro intake gaskets too. $125 plus the ride.
508-344-2649

I have a factory cast iron intake from an old 330hp/7.4, as well as a couple of aluminum factory 365hp / 454Magnum intakes.
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ok this in not a ball buster,you will need a straight plenum intake to get the engine to breath as mentioned,a stock intake for your application will choke the engine as mentioned..

if your worried about a alunimum intake corroading then you may want to look into a dart or merlin intake that has the casted bronze in the water ports..

yeah mr. fixall that's what I'm going to end up getting. I'm going to either find a dart or merlin and get it for the build along with the aftermarket exhaust. I appreciate the informative response and that's what pslonaker had advised me to get as well. I started the thread wondering what was out there but some people just jump all over someone without knowing what I'm even going to end up getting which boggles my mind. Going stock would not allow the engine to breath as efficient you are correct so hopefully I will find a good dart or merlin. Thanks

Thats a good idea. mabye you can save some coin and find a takeoff from a 500hp carb engine. also, you are gonna need a good holley carb. mabye someone has take-offs of both.

i was just saying if you want an old iron one i have one. dont care what you are gonna do with it. if you bought it it's yours. use it for a boat anchor.

What ever you read on here!! Don't tak it personal,yes their has been alot of wise cracks about the build and i have made a few myself but the john deere paint is kinda funny you have to admit.
When you start calling people names then it get's personal..

What people have stated about your old engine is pretty much dead nuts on,it looks to me like you got water in the cylinders and broke the crank but hey what is done is done now its time to move on to bigger and better things and accept yur losses..

if you want correct information you will get further with sugar then salt and most people on here dont take it too kindly when theirs too much salt thrown in their direction..

Word of advise,when it comes to the internal parts in your engine build dont cheep out with cheep parts..spend the extra $500 on a good rotating assembly because that will be the first thing to go..

Be nice and im sure you will get the correct answers..

Good post dude. My thoughts exactly on the dart or merlin intake with the brass water jackets. They are slam dunks for what this kid is doing.

Sorry. I didn't ask why you wanted cast iron. I just assumed you had your reasons.
I suggest a "WorLD Products" part no. 063034
VERY close to the marine Dart HP500 intake manifold.

Good luck with your build.
063034

The 454mag/502 mag intakes are aluminum. The 330 intakes are cast iron and are for oval port heads.