pushrod sizing

[jasmurphy]

I am completing my max effort ford cleveland.
Nascar block, 4.080" bore, 4" stroke, 6.130" alloy rods, custom max dome Ross pistons, 4V closed chamber heads flowing 724hp, compcam custom solid roller 284I 292E at .050, 794" lift at valve, 112 lobe centre (wide for 200hp shot of gas).
15.6:1 compression, custom tapered runner large plenum single plane intake, Pro Systems SV-1 alcohol carb.
Valve springs are Compcam 948 set up at 345lb on seat and near 900lb open.
My question is how do I determine what diameter and thickness pushrods I need?
With the probe shaft rockers I need a length of 8.650", but I dont know what other sizing I need. It is all well and good to say "BIG", but what do I need.
It is apparent I need to machine the pushrod holes in head on anything over 5/16 with the lift I am using, but do i need to machine alot more for say 7/16 pushrods if that is what I need?
In the comp catalogue the largest pushrods are 3/8 and .080" wall. Is this enough?

[amick]

As far as length goes you will have to use an adjustable checking pushrod to determine what length is going to work best for you setup. Nobody will be able to tell you what length to get. The question of how thick the pushrods need to be is simple. The thicker the better period. If you get a 7/16 pushrod in this motor that is what you need. If you don't have quite the clearance for a full 7/16 then you might look at something like a dual tapper 3/8-7/16. Both of these pushrod styles are in the Comp Cams catalog. The .080 wall 3/8 you mention will not be enough push rod for this setup.