Re: need to buy a 4.3 long block,who & why?
And here comes the "I bought a long block from XYZ company, because it was cheap and has a great warranty and cheap shipping.
Basically, every cheap (aka inexpensive) rebuilder takes a V8 block and punches it out to max overbore of .060. No measureing to see if a .o10 or .030 will work, just punch and run. It's cheaper that way.
However, Mercruiser, Volvo and OMC when the exited did not recomment overboring to anything over .030.
Have seen the overheat melt away telltales on many engines. If they are gone, so is the warranty. Doesn't matter if the pistons ar too tight and causes the overheat. The telltale melted. Warrenty VOID.
To produce a used long lock for $1500 or less takes a lot of slam bang, little effort, no measuring, rebuilding.
Sorry, that is called a "we think since it's boat and you won't use it much, it should last at least the warranty period, but if it doesn't we will say you overheated it."
Been there, done that. Just no one here admits it happened to them. But it does.