Join Date: Nov 2014
Location: Marshfield, MA, USA
Last 351W I had, I had a similar issue. Drilled and tapped the hole for 3/8 and used a 3/8 bolt. If you're going concourse, this is not recommended. You'll get called on it. If you just want it to stay together, this works just fine. My 9/16 wrench isn't far away from my 1/2"... just sayin'.
69 Convertible, 351W, T5, E-Brock Performer 351-W intake, Performer Plus cam, Holley 4160, power assist, dual exhaust, 4-wheel manual drums.