I'm helping out a friend install some heads (GT40) and when I dropped in the push rods (stock length 5/16" diameter) it just seemed like quite a bit of play then I remember when I did mine, even with the rocker arm tightened down I can still turn the rocker with minimal effort and make the push rod touch the sides of the guide plate. Am I just being over paranoid?? I'm wondering if since it's a 3/8" stud if the heads don't have 3/8" guide plates and require 3/8" push rods. Which I thought was more of a big block thing?? I'm not sure, any input would be appreciated. Thanks.