Is there a way to figure pushrod length without actually messuring it. Im getting my heads worked and milled .05. I plan on going with either the TR220 or lun55006 cam. I would like to order the rods at the same time as the cam how do I figure the length or can I stay with stock height, this is going on a 5.3 has anyone gone this route with the milling and high lift cam and if so would you advize for it or against it.

 

I believe...don't quote me...but the stock length is 7.4. Just for math purposes, if your shaving .05 off, take .05 off the 7.4 and get a set of 7.35's. However, if your getting a really high lift cam I'd ask the techs from where ever you are getting your cam. They won't steer you wrong. They have millions of dollars of research into what size for this and what size for that.

 

To try and keep stock geometry, Start with 7.38 for stock pushrods then you have to take the difference in base circle of you new cam minus base circle of stock cam divided by 2. This will tell you how short you stock pushrod will be. Then add the amonut of mill you are taking off the heads. If the number you now have is positive, you need a shorter pushrod (7.35) if it is negative you need a longer pushrod (7.40). With my cam, wich really dosn't have that high of lift and heads milled .040 worked out perfect with a 7.35 pushrod. I am assuming yours will come out about the same ifyour cam has higher .5xx lift(smaller base circle).