I'm afraid you're in for an abrupt learning curve here! I'm not familiar with the 3.85 SCAT crank, but most guys use aftermarket 6" long Chevy rods and any number of pistons (usually forged) that all combined, will give the correct compression distance for your particular engine block. In addition, some stroker cranks need the block to be clearance-cut in multiple places including under the oil pump, and all will require extensive rebalencing. Some combinations cannot be done conventionally and will need 'Mallory-metal': a type of tungsten alloy, inserted in the crank, to get enough weight to balence the assembly. Unless you've done this before, I suggest you take your parts to a stroker-Ford specialist for the finishing touches. This is not a typical engine put-together; this is big-league stuff and Chevy mechanics are generally no help. A local sprint-car engine builder may be able to do it if you're not in a big metropolitan area.
