Re: 1950 327 Water Pump Bolts

Posted by HH56 On 2023/4/1 17:01:49

A general rule is for maximum strength in steel or iron you want as deep of thread engagement as the bolt diameter. A 3/8 bolt at 16 threads per inch would work out to about six threads engaged and able to hold the pump -- as long as none of the threads in the block are stripped.

If the 1 1/2 length will do that they should work. Less than five threads and I would start to be concerned there might not be enough mechanical grip to adequately secure the pump with all the belt and motion forces pulling against it, particularly if the threads in the cast iron are not in great shape.