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[bakon]

117 kit.
... thinking about using .030 head gasket instead of one in kit and using stock push rods since the ones in kit are .030 longer perfect fit ones. Thoughts?

Have to measure the Head gasket in kit, but assume it's .040-045? Probably be off either way I go there.  Unless I have the heads shaved down some but I hear there is not much room on the wetheads.

[TIMINATOR]

Use the perfect fit rods or adjustable ones, either way running the lifter plunger deeper results in more power, as long as they are about .025"+ up from the bottom. Search  lifter adjustment and bleed down rates, its been talked to death on this, Harley Tech Talk, and V-TWIN FORUMS.  I've posted on all of them about that subject as have quite a few of the Gurus on those boards.  TIMINATOR

[bakon]

Thank you

[HD Street Performance]

117 kit.
... thinking about using .030 head gasket instead of one in kit and using stock push rods since the ones in kit are .030 longer perfect fit ones. Thoughts?

Have to measure the Head gasket in kit, but assume it's .040-045? Probably be off either way I go there.  Unless I have the heads shaved down some but I hear there is not much room on the wetheads.

Your change is within the tolerance of the plunger travel and as you know will just lower the lifter plunger slightly. More preload does not provide any more power or have any benefit but also no downside. There are host of myths about lifter preload. They are not jacks, just take up devices and need some preload at all times and need the proper oil supply, not any more than a stock Harley oiling system provides.

[grc]

Theoretically speaking, lifters with rapid leakdown rates might see increased lift, duration, and max power if the plunger starts out nearly bottomed (extra preload), since they can't collapse any further than "bottomed out".  Using that theory, solid lifters set at zero lash would be the ultimate answer, but of course we don't run solids or zero lash for very good reasons. I'd have to see some real test results on real world builds that showed significant performance increases due to running extra preload before I'd consider recommending the practice.

A better approach IMHO would be to buy better lifters that don't leak down instantly.  They are out there, but you'll need to look somewhere other than the MoCo.

JMHO - Jerry