Abstract: A drill guide for accurate placement of bolt holes on a mud sill or the like which includes a guide block having plural bores extending therethrough from a top face and through a bottom face thereof which are suitably dimensioned and adapted to receive a drill bit for accurate bore placement on a mud sill, in which the drill guide includes an upright which is orthogonal to the guide block which insures perpendicularity of the bores and a spring biased slide which travels in a trackway on the guide block so that the upright is yieldingly connected to the guide block to cause contraction thereof, the guide block having an end face remote from the upright with a semi cylindrical groove running vertically which abuts against an associated placement marker for accurate placement of the bores within the mud sill.