Do I need shorter pushrods?

[lahatte]

Hi. I have a 1971 383, and it has had some metal cut from the block deck and the heads for squaring and clean up. Could amount to 0.040 or 0.050 thousandths. The engine will use hydraulic lifters, stock rockers.

How much reduction in distance from the crank center do you think might require the use of shorter than stock pushrods? Can I use the stock pushrods without issue?

Thanks.

[Skid Row]

  Had a issue after extensive decking on my block. Measuring lifter pre-load at .038 using Erson push rods, (Factory recommended-
preload if I remember is .020-.040). I used .010 shims under my stock rocker shafts.

[moparroy]

Disassemble the lifters and drain all the oil out of them. Then assemble the valve train and see if you have movement / free play in the push rod / rocker line. Play will take up when the lifters fill back up with oil. If there is no play then you need to do something else. You should be able to partly collapse the lifters by hand or feel bounce in the lifter spring if there is free play.
I had this years ago when I changed a head on a 318 - when I tightened down the rocker shaft all the valves were open. I had a mech tell me to shim the shaft - to me that did not seem right - this was just a head swap. After disassembly of the lifters and draining the oil out of them all was fine.

[lahatte]

Thanks guys. My lifters are new. Have not been installed, so I should be good on checking the amount of free play of the rods, if any. Shimming the rocker arms could indeed be another option if necessary.