LakeDude

Just found out my 454 mag mpi has a busted piston. Like everybody I would like more power. Did not find lots of options for remans on the net. Talked to US Engines they offer 454 In 425, 450, 500 hp my current engine is bone stock 454mpi with stock exhaust. Qustion for you guys is what exhaust will I need? What problems will i run into with compter program? What difference in power and speed will I notice? I currently Run a 24 4 blade Bravo1 It will turn around 5000 olso have a 25p 4 blade it has a hard time getting on plane with 4 people on board, Would appreciate any advice.

GTOFFSHORE

your best bet is too just carb it. You can find power pretty cheap right now. Look at the reman marine eng that summit offers in the blueprint line. Decent stuff good power and a real warranty. As far as exhaust change over to a gil or manifold style you can find them used pretty cheap. Your heads are pretty good so you could get a intake carb and a reman 509 shortblock.
that velocity would love you

Young Performance

Your intake is going to be the biggest restriction to making power. If you use ANY other long block than an exact replacement for what you have, then the ecm will need to be programmed. It's not that big of a deal, but just keep in mind that it needs to be done. There are a few of us that are capable of doing it correctly.
You have the same intake that is on the 502 Mag, which is good to about 550 hp without some mods.
Eddie

sonicss42

I have a fresh 454 if you are interested. I can send pics and details. Let me know.

LakeDude

Thanks fellows talked to Eddie Young today