Lets see some pics and some weights. I am going to be using them in my next build, so as much info as possible is good. I keep hereing how strong they are, I would like a bit more info.
The LY rod was the beefiest internaly balanced rod made. 6.76 inches in length with a 1.094 pin. They weigh around 850-860 grams, and have a 2.375 big end.
I know personally, with a VERY heavy Speedpro piston, I was able to turn 8500 RPM without failure for 15 years. When I did break it, the block actually broke at the lifter galley, causing a chain reaction which snapped a rod (part of the block jammed between the rod and the block causing both to break). So the failure is suspect, and may not have been the rod's fault.
The heavy 6 pac rods were designed for the super stockers turning 6700 RPM, but it was discovered that the lighter LY rods not only did the trick, the ability to internally balance and have a lighter bob weight was preferred.
I wouldn't say 440's are rare, there are plenty of sources around to get them. However if you are going to compare a 440 to a Chevy 350, well, there aren't nearly as many of them. The Mopar Big block ended production in 1978, which is why you don't see them in new boat / cars / trucks. However certain limited factory options are rare, such as cross rams, long rams, 6 pac's etc. Those go for big bucks and mostly are used by the "factory" guys trying to replicate the best there was from the factory in 1970.
Mopar was always big on induction - The Ram Chargers invented the modern day tunnel ram, and had wild factory induction like the long ram manifolds (the carbs hung out over the FENDERS!) which peeked out at 4700 RPM, had 6 pac's, holly 4bbls, and the all plastic 1000 CFM thermoquad with 2.25 inch secondaries which kept the fuel cool to allowed higher compression. They also worked on the exhaust - anyone ever hear of the factory cast iron headers? Heavy but legal in stock class racing.
They were a big bore, short stroke configuration, which is great for RPM potential. The one nice thing about mopar is - they don't change stuff unless they absolutely have to. None of the gee this manifold will only bolt to these heads, which only fit this block. Pretty much you can get any BB mopar, and everything from every year will bolt on. No different lifter angles, no pattern changes, no funky block heights.
There are 3 blocks, the small block (LA), the B (383-400) and the RB (413-440).
The stock small block can go to ~430 ci, the B 512 ci, and the RB 543ci. This assumes the max overbore on the stock block. With aftermarket blocks, the cid can go higher, and with raised cam blocks, even higher still. A standard KB aluminum block can handle a 4.75 stroke, 4.6 bore or 631 ci. I actually don't know what the raised cam blocks will handle.
Now that the Chevys have been played out and there is so many incumbants for heads, blocks, etc; other manufactures to grow market share first started with Fords, and now they are getting into the Mopars. When I started, there wasn't ANY aftermarket parts. You mixed and matched factory parts until you got the right combo. There used to only be one stroker crank, a 4.15 stroke, which ran about $4500 but gave you 512 ci. If you didn't want that much, then you took your 3.75 stock stroke 440 crank, offset ground it to the 2.2 inch BB Chevy size and with the right pistons and Chevy rods, created a 470 ci engine. There was .070-.090 rod side clearance, but it didn't seem to affect anything but oil pressure. A HV oil pump took care of that. Nowadays you can get a rod with a Chevy bearing size, but a Mopar width with either Chevy or Mopar pin.
Now, there are many rod, block, head, and crank manufacturers, so you can build pretty much any combo you want. Look at Edelbrock and 440source for heads. Cheap nowadays. I spent 6K on my bulldogs on the 528, if I would have waited several years, I could have gotten something much cheaper.
On the boat engine, I took a 400 block, a 440 forged crank, the 400 rods, and bought an off the shelf KB piston to create a 451. The 400 is a Junker smog motor, so no one wants them. In reality, they were just low compression with smog controls and lean burn ignition, they really had all of the same parts on them as the "good" engines. Most rebuilds change the pistons anyway, so that isn't an issue. Swap out the ignition to an MSD and jet up the carb, and suddenly all of the issues with the 400 go away.
I got the 400 for $250, recond the rods for $125 inc ARP bolts, the pistons were $250, and I cut my old 440 crank for $200. Not a whole lot in the engine. While I decided to use my race heads I had in the garage, I could have easily used the 452 heads that were on the 400 engine.
The one feature (in addition to block and crank strength) that really would be benificial in a marine engine, is the oil system. Oil has NO issue getting back to the pan - factory big blocks survived with a 4 quart pan! Obviously for reliability reasons when using a sustained high RPM configuration (or racing) you want more oil, 6-7 quart pan is all you need (more doesn't hurt, but not needed, even with the 20 GPM KB billet pump).
Post more later.