Went to adjust the valves on my MP 426 crate motor and 2 of the adjuster screw lock nuts galled on the threads.Went to order new adjusters through summit and they offer 2 sizes 3/8-24 w/ 5/16 ball and 3/8 24 w/ 3/8 ball. Their web site says the 3/8 ball is correct for the Hemi BUT the adjusters in my engine are the 5/16 ball adjusters. Which is the correct adjuster for a hydraulic cammed hemi? Thanks, Charlie.

I'm not sure what's "stock" but you don't have stock, you have a crate motor. So, for you it's the 5/16" ones that match your push rods & the rest of your engine.

3/8-24 with 5/16 ball

The adjusters on the MP crate HEMI's are just ticking time bombs, I've dealt with a fair share of the adjuster balls breaking off, as well as other adjuster maladies breaking on various 426 and 472 MP crate HEMIs


Replace all of them before you find yourself in a real mess, either Crane or Smith makes quality replacements, the ones currently in your engine are from Comp Cams, as is the cam

Thanks, just ordered a full set of crane adjusters from summit with 5/16 balls. I will change them all while I have the covers off. Thanks again everyone!