I have a set of comp magnum tall lifters in my new 383 that I'm hoping to start up this weekend. Comp says to set the lash at .002-.004 with the engine hot. Not a problem. My question is, what do I set them at first so I can start the engine and get it nice and hot?

 

Iron block and aluminum heads I would suggest .000 lash. No preload, no lash. Its not something you need to sweat. If you're off a few thou it won't matter. The only thing they don't want is to have more than .004" lash or so because a hydraulic roller can get fairly aggressive up the ramp and hurt the lifter needles and make noise when it comes crashing together.

 

So basically run the polylocks down to where the pushrods have some drag on them and start it?

 

Yep, that will give you a little preload and that's fine. The lifters run with lash and operate with the plunger against the stronger snapring so there is no chance of "pumpup" at high rpm. Firing it up for the first time you can set them like you would a normal lifter and they would be happy.

If you're shooting for .000" lash you won't feel any resistance rotating the pushrods with your fingers.