Threads on a Dart Block

[Tim Kay]

It's been a couple years now since I had may motor worked on by others. In tracing a water leak I discovered a bolt missing at the water pump. All the adjacent bolts are ARP and for trial sake I inserted a standard 3/8 bolt but it is very tight around the shoulder and when it reaches the threads it will not continue. ( It's one of the long bolts, approximately 3.5". )

Am I assuming wrong and possibly this requires a metric thread? It's a 351W Dart Aluminum block. TIA

Tim

 

[Jac Mac]

Everything on the front of a Dart Alloy SBF block for timing cover is 5/16" UNC unless someone has changed it or made a non std repair.

 

[Tim Kay]

Makes sense, thanks a million Jac Mac.