I just finished a cam swap, and put in new Caddy racing lifters to.
I soaked them in oil for about 3 days, but I know that doesn't let the oil get deep inside the lifter...understand that now that I've taken one apart, the seal between the 2 parts is almost air tight where the spring resides.

Anyway, I primed the oil pump until oil trickled out of all of them, but even that would not allow oil to fill the cavity where the spring is.

I put not quit a 1/2" turn of lifter preload on them, around 3/8 of a turn...started it up and it was extremely noisey...alot of that went away within 3-4 seconds, but the valve train still makes all kinds of tapping noise like all of the rockers are loose or still not enough pre-load.

I drove it for about 5 mins under 2k rpms and they never quitened down.
Cam is a LPE 211/219 .530/.560 lift with 1.6 Comp ProMag rockers.

Once it cools I'm was going to take the covers off and put 3/4 turn preload and see if that helps, but I'm wondering if these lifters should be fully pumped up at this point???

The stock lifters could never be pushed down any by hand once full of oil, so I'm curious to see how these or stiff they are now that they've been used a few minutes.

 

As soon as you see oil pressure, the lifters will be pumped up.

 

maybe you should try to adjust them while the car is running, i had better luck that way

 

Well I readjusted all of them, this time put 5/8 of a turn preload...still noisey, but not as bad.
My truck has the same exact cam and rockers and its as quiet as stock, but I have no idea how much preload were put on them.

About to take the cover back off and put a full turn on them just for the hell of it...if that don't do it, I guess the intake is coming off and I'm going back to stock lifters...

There's one or 2 lifters that are not hard to push down, a little force by hand pushes the pr/lifter down some...is that normal??? My stockers were always rock hard when you pushed on them like that.