351W coolant temp sender size?
 

Earlier I went to try and install my Summit Racing coolant temp. sender with gauge (http://store.summitracing.com/partde...5&autoview=sku), only to figure out the bolt(?) size is different from my stock coolant temp. gauge's.
The threads seemed to be the same though (I put the summit one in not realizing it was a little bit smaller at first).
The location calls for an 11/16" size bolt, but the new Summit one is 5/8". Very close, but no cigar. I can't seem to find an adapter for these sizes anywhere... any ideas?
There doesn't look to be any adapters with an 11/16" male end... really would like to get this new sender/gauge in so I can know more accurately what I'm running at... but the stock bolt size is really screwing me up.