Right Angle Oil Filter Adapter Mounting Bolt Question

I was attaching the right angle adapter on the 273 the other week. Unfortunately, I snapped the large mounting bolt. I was able to remove the threaded portion. I ordered a mounting kit that came with gaskets and a new stronger bolt. Unfortunately, the bolt is short and won't engage the threads of the block.
Where the bolts longer on the original cast iron adapters? Anybody know a source for a correct bolt?
Thanks in advance