Offshoreonly.com - 454 to 540 short block?

Quote:

Originally Posted by MILD THUNDER (Post 2065420)

You are right Frank. My boat originally came with 400HP mercs with 3" cast iron logs. I ditched those last spring and went with the Cast Iron "420HP" manifolds with the Gil tail pipes. An improvement over the 3" for sure, and I would think still better than the 4" standard merc iron manifolds. The guy I got them from ran them on a pair of 550HP 496's. He then swapped them for a set of CMI headers, and he noticed a slight increase in the midrange, but not much on top. The drawback is the wet joint that is prone to leaks. Mine have been ok, but none the less, a pair of aluminum manifolds would be nice. Not too mention the weigh savings, these suckers are HEAVY!

My boat tops out around 58-60 right now, Id like to see 65 or so. Who built your motors Frank? They sound sweet, and I know that thing runs!

Thanks, yes it does run quite well.:D The engines are a fairly mild turn key 580 cu in. Hyd roller cam, Dart 360 heads, and alot of help from Dave Wesseldyk up at Wesco Racing engines in Mich. I built the engines, took them up to Daves shop, and while they were on the dyno, Dave gave them a once over, and found quite a few things that he recomended I change. I let Dave take the engines apart and make the changes he wanted to, and I'll tell ya what, if I did'nt, I would'nt of had too good of boating summer.:rolleyes:

If I were you, I would really seriously think of at least talking to him about your situation. He's gonna tell you the truth if it's good or bad, and sometimes he kinda bursts your bubble, but the one thing he will not do, is give you an uneducated guess of what you need to do to achieve what you're looking for, or sell you a pile if crap that you really don't need. There's "too many" scammers out there that just want to get into your pockets for the most they can. He's not one of them.

Daves shop # 616-662-2250....... tell him you're another one of the "chicago" guys from Diversy. He'll take real good care of you, I'm sure. He already builds and maintains the boats for Austin's 47 Apache, Mike's 47 Fountain, Chads 41 Apache, Mike's 38 top gun that was bought by one of our club's board members (Jamie), Chi Town Hustler, big Rick's 2 46 Cig rough riders, one that's getting a pr. of 1200's in it, the one that we had in the harbor last summer, and another one that he just bought last month that's getting a pr of 1300's built for it. And of coarse, my boat should it need any "serious"
attention.
Good luck on whatever you decide, but remember it's going on the end of march, and there's not much time left to finish a big project befor summer.