Ok so the other day one of my spark plug holes got messed up and I pulled my head to fix it and noticed my comp magnum pushrod length is 7.400. I could of swore that Trickflow said that you need the 7.500 PR with this this head "not milled" and the stock size (.51) gasket on a LS2. Well I actually had a problem before with one of my pushrods busting through a rocker arm last year and had a race shop look at it and they said they looked at the pushrod length and said that my 7.500 pushrods (previous) were to long and that is what casued it to go through rocker arm! So I told the mechanic to replace all push rods, and rocker arms, and measure for the right height PR's. First he said they were .150 off and that I really needed 7.350 PR's so I go ahead and buy them and he puts them in. The next day he calls me after i get him the pushrods and says he messed up on the measurement and that I actually need 7.400 PR's and not to worry about it and he will buy them and not charge me. If the PR's were off by say .25-.150 could that make me loose 25+hp in the high rpm? Is that why I am only making 485\485 on E85, 403ci, HCI + all boltons? Does the 7.400 sounds right?

 

There's only one way to be sure for certain and its measuring it. I see that the stock size is used often with the stock heads but with a TF I would think they have a thicker deck? You can do this yourself and it's pretry easy in my opinion. With aftermarket heads like yours or with milled or thinner head gaskets I would measure it myself but that's just me.