Re: What block to use w/ 434 c.i. stroker kit????
Actually I believe the 509 casting, while only a 2 bolt, is the most highly sought after of the 400 factory blocks. The reason are the 511 had less material in it's thinner main webs. These were beefed up in the 509 block. Also the 509 was a high nickel block, I don't believe the 511 or 817 were. Not sure on the 817. Some 511 replacement blocks were actually only 2 bolt, although rare, they would still have the thinner webbing. Another member reported recently that his machinist showed him the 509 block was 10 pounds heavier than the 511, that's significant. Many say the ultimate 400 factory build is a 509 block with splayed caps. But I feel that splayed caps would be a waste of $$ on a factory block. First because they have stepped registers and second you don't need to go splayed until you are making enough power that you should already be looking at an after market block. That's why i plugged my splayed holes and skipped the align bore, just went studded 2 bolt with the factory caps. They'll be good for the HP that the factory block is is rated for. Not going to spray it ever.
Bottom line though is going beyond .040 is a risk, hopefully you'll sonic check it first. Also the factory blocks have much thinner decks, which you'll need to cut get your quench right, so that makes it even thinner and these decks are known to crack. They've also got thinner cylinder walls. Also not all 400 factory blocks have the same number of coolant holes, make sure you've got the large hole between the center two cylinders on the exhaust side of the deck.
A 434 may be able to be made to fit, but anything beyond 550 hp you should start looking at an aftermarket block in most people's opinion. I've got a 509 block ready to go together, but I'm struggling if it would be wise to try to go 420 cid with it evn though it's short filled, decks plugged, studded, clearanced, ect.
"..............what, and get out of aviation??"