Thread: bore an ls4?

Im new here, and notice that alot of ppl have done some interesting things to there GXP's. but there also seems to be a small selection of aftermarket parts. i just recently bought an 2007 GXP, and wanted to know if anyone here has ever experimented with boring and sleeving. from my understanding the outer diameter of the 5.3 sleeve is roughly the same as a 5.7 sleeve, with in a few hundreths of an inch. I would guess that no stroker crank exists, and would be astronomical in cost to mill one.