Originally Posted by Pwmax
My advice, first off, listen to what Ed said, if you use a 400 block. With that said, I would use a Dart 9.325 spread pan rain, raised cam block, and build a 434, or 440 or, with a 4inch crank, or use a 4.125 crank for 447 inches, or 454 inches with the 4.185 bore. This block eliminates all the negatives, to a stroker crank in a stock 9 inch block. Way easier to clearance the pan rails area, just needs a litte touch up for the rod bolts, the cam is up out of the way, and, get the BBC cam journal block while your at it, that eliminates the issue of cam to rod interfearance, and the extra deck height, allows for a 6.2 or 6.250 rod, whith a good ring stack on the piston. Plus, in my opinion, stock 400 blocks are junk. Unless you fill them to the bottom of the water pump holes, plug the big deck holes, put billet caps on all 5 mains, they are an eggshell for big power. For a mild street or bracket engine, they work fine, using the stock stroke, and 5.7 length rods, they can be brutal street/strip engines, but, definately have their limits
Frank
Advanced Performance
www.get-ap.com
My thoughts as well as we have seen to many 400 blocks scraped after a hard season of running due to cracking.
And going with a spread pan rail and raised cam tunnel allows you to go to a BBC cam tunnel or 50MM roller cam bearings, Using those small base circle cam allows for cam twist and more radical valve action over a bigger base circle cams which allow for smoother valve action.
One other point is the better blocks have proven to make much better horse power of a OEM blocks as find cam tunnel placement and lifter bore placement out up to .025 and if you have lifter bores off up to .025 and if your using a roller cam, Roller cams and roller lifters work on exact center lines and if a lifter bore is off from intake to exhaust it changes the seat timing events a ton now times that by 16 lifters.
Now add to the equation cam tunnel placement as we have seen them off up to .014 from blue print.
Joe Sherman went form a 400 block to a Dart or World block with the same components and saw a 40 horse gain over using a stock block.
After what we have seen over the years using a 4 inch stroke crank really requires a good soild foundation.
It all biols down to what you can really afford.
At our shop if a customer wanted to build this type of engine and wanted to use a stock block we would just pass on that job as I would not feel comfortable using a stock block for that much cubic inch.