Chevy Crank stroke?
 

i hope if your planning on building a high rpm motor,your planning on putting it in a reeeeally light car or your better off thinking the opposite!

366T = 3.935" x 3.76"
396 = 4.096" x 3.76"
402 = 4.125" x 3.76"
427 = 4.250" x 3.76"
427T = 4.250" x 3.76

348 = 4.125" x 3.25" (6.125" rod)
409 = 4.312" x 3.50" (6.010" rod)
427 = 4.312" x 3.65" (6.135" rod) 1963 "Z11" SHP drag race

so to answer your question 348 has the shortest of these but im not sure if its considered a bbc that your looking for...probably the 366 to 427 would be shortest id use for high rpm...but then again i dont remeber seeing a gooood steel crank with that short of an arm(4340)