Valve Train

[1970FordTK]

Have a few quick questions on the valve train, being that I'm not use to working with a non adjustable rocker system. Push rod length change for slack adjustment I can understand. But if you can turn the push rods with the valve closed, is that too much slack or is it ok. How thick a feeler gauge is ok to be able to slide between the valve top and the rocker arm when the valve is closed? If the truck has 9.59" push rods now and 6 of them are short enough that I can put .028 gauge between the valve and the rocker. The others are little slack and some have no slack but I can turn the push rods on all of them when the valve closed. My plan is to replace all of the push rods with 9.62 rods, will that be to much change for the ones that have no slack? Any idea/opinions will be welcome, motor is a 360 that has recently been machined/rebuilt. Cylinders where homed along with new rings with pistons-bearings and heads rebuilt also. Same old rocker assembly, wich I figure has some wear. Thanks in advance folks.

[My427stang]

Here is what I would do.

If the intake is off, look to see how much the lifter plunger is depressed on each lifter when that cylinder is on TDC

You need to know how much the plunger depresses, the slack test you are talking about doesnt really mean anything. Odds are you probably can just reuse stock pushrods.

The plunger should be compressed .020-.060 when the cylinder is at TDC, then turn the motor90 degrees and check the next one.

Now, you'll have to take it back apart to put the intake back on, but its really the only way on a non adjustable FE I know to check preload properly.

With that being said, I have NEVER needed to change pushrod length in a hyd cammed FE, even with up to a 292 duration cam.