Joel5.0

Those engines, like the OEM pedestal setup in Mustangs, make the PR length variable more important. I've worked on gm and other Ford setups repairs (mainly HG failures/overheating) that have required PR's to be replaced for shorter ones after the heads have been milled (.045" in one case alone). FYI...HO stock setups came with ± .060" PR length from the "normal" 6.272" gauge length pushrods from the factory, and are available for stock setups if a "collapsed lifter clearance check" falls out of its specification.

wolverine8490

It really just blows my mind that all of this does not make sense to me. I mean, I have been working on cars for years now, and this is the first time I have ever heard of checking the pushrod length. I mean, I never worked in a shop. Although I did go to vocational school for 1 year, but the teacher sucked, and did not give a care in the world to teach us anything. But this is the first time I have used aftermarket heads, and the first time working on a ford. I guess it is just really hard for me to think that the pushrods are wrong, when trick flow sells them in the kit. But from the way I understand you, it depends on the deck height, if the heads were milled and so on. Do lifters have different lengths?

Either way, thanks to all you guys for trying to explain this to me. I never liked adjusting valves, and never understood why they could not just provide a torque spec. But the more I read, the more I am starting to understand. The whole zero lash thing still bogs my mind. I mean, wouldnt zero lash be different in a lifter that is dry and a lifter that is pumped full of oil?

Any which way, here are the specs of the pushrods that came in the kit:

__________________________________
ForUsewithGuideplates:
Yes

TubingDiameter(in):
5/16 in.

PushrodMaterial:
Chromemoly

TopTipStyle:
Ball

BottomTipStyle:
Ball

IntakeOverallLength(in):
6.700 in.

ExhaustOverallLength(in):
6.700 in.

Quantity:
Sold as a set of 16.

OnePiecePushrod:
Yes

Oiling:
Yes

Tapered:
No

TipAttachment:
Formed

TopTipDiameter:
5/16 in.

BottomTipDiameter:
5/16 in.

WallThickness(in):
0.080 in.

Heat-Treated:
Yes

irish1

You shouldn't have a miss for sure, but theres only 100 miles on the fresh rebuild you said, she isn't broken in yet, it is quite possible the rings are not fully seated yet. Try adding a little oil to a cylinder then testing it and see what the numbers do. Also warmed up would be good. Another thought is what pistons were installed? Just curious, how is your oil pressure? I have a 306 with about 100 miles on it, mine is at 70 cold and 50 hot at idle. Hope that helps...
Matt