Well this post just saved me, I am also refreshing my 502Mag MPI and adding roller rockers. I will be knocking those tabs off ASAP! LOL

My boat would not pull past 4,600Rpm with a 22p 4blade prop and would run 59mph and just started dropping from there. Decided to pull it and found teo different head gaskets. The original one is toast between the cylinders along with exhaust seats very pitted due to reversion.

Yes my kid is looking for a ball he threw in the bushes lol

Unfortunately, common for the OE headgaskets.

Do yourself a favor, since a part, and get those injectors to ArticFriends. :thumbs

Are there better head gasket recommendation for the 509? It seems to me that these engines blow head gaskets a lot because the cylinders are so close together? No real-estate to speak of to maintain the seal. Or is it surface prep? Combination? Just curious.

Just the OE gaskets are an issue. The felpros are fine. Some go mls but imho not really needed unless yuge power.

The entire MPI setup is not going back on, I am going with a Holley EFI setup consisting of Holley HP ecu, Holley 4150 style intake with throttle body and multi-port injectors, Holley distributer ignition box and distributer.

100% putting a set of MLS gaskets back on none of that crap paper material stuff. You can see apparently my engine blew one already as I found the stock and a Felpro on it.

Ok so the so turns out my heads are cracked I found a good set of ls6 heads it had 990s but the engine shop here is telling me if I put the heads on it will prob increase my compression ratio to much and it won't last at all any one know if I can run em?