The 4.100" strokes are a not a good geometry for the short sleeved blocks. Resleeving corrects this but that is alot of expense for marginal if any improvement. The 4" stroker kits are more than enough.
I have personal experience with the 4.100" strokes and I am not a fan at all. I personally had a LS7 bored at 4.135" with the a Callies 4.100" and it was not as well of a performer had it been built with the 4" stroke. My block was not resleeved and it tended to consume oil. I had a friend with a 6.2L block with the 4.100" stroke the LS3 427 ci. It was also not resleeved and it consumed even more oil than mine. I caution eveyone that asks about the 4.100" strokes. My personal exerience is that the LS series engines do not respond very well to over stroking either. A square build is as far as I would recommend any LS engine be. The 4.125" bore and 4" stroke has proven to be very difficult to improve upon. Many wild combinations of engine builds out there and none clearly stand superior to the LS7 stroke and bore no matter the block selected.
"old age and treachery will always overcome youth and ambition"
"There are two types of racers: cheaters...and losers."