Not that this answers the OP question but i thought it was ?interesting?...this is a bent checker pushrod which is 5/16 and about .085 wall. I was capturing the difference between the checker spring and the actual spring which is about 750lbs open to gauge system deflection. this is an 8.7 long pushrod using an SR head and offset lifter and homemade spacers to straighten the angle. Actually snapped about about 3/4? the way to peak lift so 600? lbs. I didn't believe it so i swung it around to the exhaust side and wouldnt ya know if snapped that one too...lol I used Manton 7/16 straight with intergrated meter orifice for PR oil regulation....VERY HAPPY with MANTON service and price BTW!!!