65shelbycone;
you had asked why long (connecting) rods for a stroker build. The reason is more torque. though at some expense to fast reving. This is due to the fact of decreased piston to cylinder wall friction that is intrinsic with longer rods, as well as a slight increase in volumetric efficiently, which, as David Vizard,engine builder,dyno expert and author, declares, "comes about because the longer rod delays peak piston speed, and thus peak air demand, till later in the stroke, when the intake valve is open further"; in other words, the pistons in a long rod engine have a bit more dwell time at TDC and BDC, even more when coupled with a longer stroke, and this lets valve events "catch-up" to piston and crank position better, while decreasing frictional losses at the same time. A nice "win-win" for the engine builder.
Longer rods work well in standard stroke engines, too - you just need the right pistons. In a 351w, most stroker kits above 383 CID come with longer rods, but check to be sure, though this is not likey as big a factor as it is in Chevy strokers , where the 400 sbc rod has a poor rep for premature bore wear and noise.
More or less, if you are replacing pistons and rods anyway; well, mine will be longer than stock.
Just my 0.02
cowboy33713