Saber-
The 502, 9.8 inch deck block can be used for a 540, but if you are buying new blocks, I would go with the 10.2 inch tall decks. At 540 cubes the 502 block is near maxed out, but the tall deck is on the lower end of it's displacement range. You could go with a slightly larger stroke and leave plenty of room for an overbore. The tall deck can use longer rods which give a better rod-to-stroke ratio.

Check Speedomotive for rotating assemblies, and also for cost comparisons. World products makes the Merlin heads, which are said to raise horsepower 50-100 over stock HP heads.

Don't create problems for yourself by mixing different valvetrain components. Get them from 1 source and check valve spring tension, valve-piston clearance and installed height before putting the heads on, and valve spring clearance at full open with valves lashed BEFORE hitting the starter button or key. I have seen a lot of engine problems posted on this board because those things were not checked.

Good Luck
Bulldog

KAAMA, when you're ready to sell those tired 540's let me know as I'll be needing them for the next (and last) boat. I can scrape together a couple bucks.

SABER28,

Give Callies a call. They make some of the best cranks and will supply rotating assemblies. I have heard bad things about the Eagle cranks, machine work sucks, but I dont know that for a fact. I know when you mike a Callies crank it will be right or they will replace it..

Another option is a new crate motor from GM?? I heard they were offering a 572" motor around 700hp. Not sure how marine it is, but I had a Gen V 502 and never broke the rotating assembly.. always the damn roller lifters. So now I run flat tappet and no problems so far this summer.

Good luck, let us know what direction you go..

Dick

why do you think most of the companies limit themselves with 540's?

what are the disadvantages of xxxlarge engines on water..like 600+ cu's

once I spoke with a famous engine builder in states and he told me xxxlarge engines loose power sooner than smaller engines.?what can be the reason to this?

Steve whats with pushing the 502???why push 502 ci hard when you can get it easier with 540 ci ???? bigger is always better!!!!

There's reliability in cubic inches.

Gadgets, a you sure?....a GM 572" crate motor??? Must be a new release eh?

Kaama you going to make me a great deal on those 540 short blocks????

thanks for the input, what i am looking for is very specific details, brands and part numbers that you guys have used. tell me what worked and what didn't. i definately will be building 540's so 502 advice, while appreciated, isn't what i am looking for. i don't want to build two ginea(sp) pigs. i want to build them and use them, not repair them, thanks

I agree bigger is always better when it comes to making HP. But he is only looking for 600 HP. That can easily be gotten with a 502 and it will be turn key. You have seen how my engines run and they are turn key and havn't been apart in three years except for bad rocker arms (6 years old ) and that can happen to any motor. I am pulling them out of the boat this fall to repair the water leaking in arround my tiller arm shaft and while I have them out I plan on doing some more TINKERING.

Stop in at Wesco enterprises in Hudsonville talk to Dave Wesseldyke he wont steer you wrong .....he might push some high priced parts but tell him what you want to spend and He will take care of you. Try and stop early in the day before he gets to far into something!!His shop is on 18th ave north of Chicago Dr. go north on 18th turn in at Harbor Master(right) go to the very end of the complex look for the boats and other really cool ****!!!!