Hey Guest!
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
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smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
Simon TR4a
Jedi Knight
Offline
Hi Rick!
Not likely the pushrods are longer but quite likely the head has been skimmed to increase compression ratio or to correct a warp in the head.
You can compensate by either obtaininf shorter pushrods or by shimmong the rocker arm pedestals; important to do this so as to get the correct geometry between rocker arm and pushrod.
To answer your question, a machinist can measure the lift of the lobes and lobe separation angle to compare with stock specs or can measure lift at the valve or rocker. Stock specs are in many catalogues or your workshop manual. You can also have the combustion chamber cc'd (head must come off) to determine the compression ratio, or the thickness of the head can be measured to compare with stock to see how many thou have been skimmed off.
Simon.
Not likely the pushrods are longer but quite likely the head has been skimmed to increase compression ratio or to correct a warp in the head.
You can compensate by either obtaininf shorter pushrods or by shimmong the rocker arm pedestals; important to do this so as to get the correct geometry between rocker arm and pushrod.
To answer your question, a machinist can measure the lift of the lobes and lobe separation angle to compare with stock specs or can measure lift at the valve or rocker. Stock specs are in many catalogues or your workshop manual. You can also have the combustion chamber cc'd (head must come off) to determine the compression ratio, or the thickness of the head can be measured to compare with stock to see how many thou have been skimmed off.
Simon.