From mild to wild! Building a 540 or 572?
#1
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From: Pensacola FL
I ready to start to new engine project. I have a 502 mag/mpi 1999.
It's on it's 3rd rebuild, all before my time. Most likely only pushing about 450hp.
But how much stock 502 parts can I use on a 540 or 572 short block?
Can the heads be worked or do I need to buy some new Dart Pro Comps?
Only looking to get about 650hp, only running a fresh bravo 1.
Thanks
Bob
It's on it's 3rd rebuild, all before my time. Most likely only pushing about 450hp.
But how much stock 502 parts can I use on a 540 or 572 short block?
Can the heads be worked or do I need to buy some new Dart Pro Comps?
Only looking to get about 650hp, only running a fresh bravo 1.
Thanks
Bob
#2
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From: On A Dirt Floor
Easy.... 540cid. For I/0's 600hp can be done dependable out of 502's. 650hp out of 540's. Low/mid octane fuel to boot.
I would not call either 'wild' though.
You can re-use the stock block for the 540. That's about it.
Do you already have good exhaust ? If not, add that into the factor.
I would not call either 'wild' though.
You can re-use the stock block for the 540. That's about it.
Do you already have good exhaust ? If not, add that into the factor.
#3
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From: Pensacola FL
Im thinking that the block is worth more just selling it. The engine runs fine, just want more HP. I'm set on building a new short block
And heads. Adding a exhaust system too. Can I reuse the intake and the EFI system?
And heads. Adding a exhaust system too. Can I reuse the intake and the EFI system?
#5
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From: Pa
It doesn't cost any more to build a 572 over a 540. The stock manifold may just work like a restrictor and keep your power down. What size boat, and what do you want to do with it. Are you ready to upgrade the fuel system and drive.
#7
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From: Pa
I don't know, you build a 650hp long block with really good heads and bolt on a manifold that was designed for a 420hp motor. I would think you could bolt on an aftermarket EFI manifold from Holley or Edelbrock, the Fast 1375 cfm throttle body, use your harness and reflash your ecm.
#9
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From: Pa
You can use it, other people have, they port them out, design new fuel rails, cut down the runners, use larger throttle bodies. The aftermarket with a carb hat works well with the Procharger and probably flows more right out of the box.
#10
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From: Cape Coral FL
I have a 540 with the stock intake and fuel injection setup off a 454 mag mpi(should be the same as yours) makes 575hp. I have talked to 3 of the top engine guys on this site and they have all said the same thing, that is all that the intake will flow. All have recommended ditching the stock intake and installing a Holley or FAST efi setup. They claim a 50hp gain just by changing intakes. I plan to swap mine out this winter.
Mine runs great and is a HUGE improvement over the 454mag, but will only turn 5200 rpm no matter what prop i put on it. Something to consider.
Mine runs great and is a HUGE improvement over the 454mag, but will only turn 5200 rpm no matter what prop i put on it. Something to consider.
Last edited by snapmorgan; 09-06-2011 at 09:45 AM.


