didn't see where you mentioned the cam that your using. if i'm not mistaken, the pushrods are only one part of what you need to look at. I ran a 356 cam last year with a 100 thou milled head. stick ratio rockers....and I ended up needing and using a 5.175 pushrod to make things equal out. as a suggestion, I would look at the cam, what ratio rockers i'm going to use, what the head is milled at and then determine the length of the pushrod needed. this year i'm backing down on the cam to a 275, milling a new head about 80, 26 pound springs and champion rockers....so I need to look at the same thing....what size pushrods do I need to bring everything in line?.....