I think the bore spacing is 4.4", the same as all chevy small blocks, including the LS
David,
2003 GMC Sierra Denali, LQ4, AWD, AWS, 4.10, Wheatley 93 tune, LT headers, GMPP CAI, BBK 80mm TB, MSD wires, E3 plugs, 160* T-stat, Flowmonster DI/DO, cutouts. Working on 4.8 heads, just purchased Comp 228R cam, 918 Springs, TI retainers, 7.4 hardend pushrods,