I have been looking at 383 stroker kits and noticed that there are two different kinds. One comes with a 5.7" rod and another comes with a 6" rod. Does anyone know besides the obvious size difference what the difference is?

the 6" rod has lighter pistons on average due to the higher pin location and less bore drag as the angle of the rods to the bore wall is slightly less, in theory the longer dwell time the longer rods provide add a small bit of high rpm hp, in REALITY the longer 6" rod places the piston pin in the oil control ring and its a P.I.T.A. to use, theres been dozens of dyno tests done , the differance is negligable and the 5.7" rods are easier to work with.
ITS FAR MORE IMPORTANT that you sellect rods with 7/16" ARP bolts, rather than the weaker 3/8" rod bolts as the rod bolts are the weak link

heres more info
http://forum.grumpysperformance.com/...php?f=69&t=263

http://forum.grumpysperformance.com/...510&p=633#p633

yep, longer rods are abit more beneficial for turning rpm due to lighter piston weight. Difference is significant. But its only important if you really want to turn some rpm or not.

I have 6" rods in my 383 and it does well all the way to 6800 rpm where the limiter is set. Peaks by 6300 and i shift by 6500

A 6" rod will need short skirt pistons and from what I've been told by a few enginebuilders that will not be oil ring or piston ring friendly on the street. I don't know, accelerated wear maybe? I ditched my 6" Rod setup for a 5.7" rod awhile ago when I built my 383.

i only put 1500 hard miles on the motor this year, and i'm tearing it down already... but i never had problems so far onthe street... never gave it time to tell tho

I don't think the rings would be a problem with the tight bore clearances run by most pistons today. I went with the 6.125" rods in my new 370 motor.