Details
GMC frame
Top flange has an overhang on engine side to a 12 1/2" overall header size. Top flange has a total of 14 holes, 9drilled clearance for 5/16" bolts and 5 tapped 5/16" N.C. threads. Bottom flange has 11 holes, 6 drilledclearance for 5/16" bolts and 5 tapped 5/16" N.C. threads. One bracket at top of frame with a 7/16" diameterhole. Two sleeves welded on gussets on engine side to accommodate cross bars. Eight 5/16" N.C. threadedholes on sides of rail, 5 on engine side and 3 on grille side. Twelve 3/8" threaded holes on flat side of rail.
Note: side frames are not interchangeable.
(left side shown here.)
