I did a cam swap to a Howard's hydraulic cam. Installation and break in were done per the instructions and went well.

I've got about 75 miles on it, and I noticed a lot of valvetrain noise from one side of the engine. I pulled the valve cover to see what was going on, fearing that I'd wiped a cam lobe. All the lifters were still preloaded, just like when I initially adjusted them, but on two of them, you can grab the rocker and easily push the pushrod farther into the lifter. The other six on this side of the engine feel right.

I haven't called Howard's yet because I wanted to ask you folks first. What are my options at this point? Since those two lifters are already broken in to the their respective cam lobes, replacing them seems risky. Does it sound like the lifters could be repaired (new guts put into the existing cases)?

Thanks!

You can just replace the lifters .You can put new lifters on an old cam put not old lifters on a new cam. You might want to do the break in again after the swap.

If you want to try to fix those two lifters you can either dirve it for a while longer or remove them and take them apart to see what you find. I've have a tiny bit of debris in the poppet valve beteen the cup and the main body by taking them apart. That was a long time ago(mid 1990s) on some hydraulic lifters that came in one of Ma Mopars old milder grind cam kits
That valve is in a cup that pulls off the base of the pushrod seat bottom,it has a tiny spring and seat inside it
Let us know what you decide to do and find out

I wouldn't be afraid to swap in the innards from another lifter even used ones & see what happens. keep everything in order. the bottom face that contacts the lobe is unchanged so I see no harm no foul & it might take up the play & solve it.

Thanks for the info guys!

I'd run it again to see if you could repeat those results(same two soft, and only those two).

In the past several years, I haven't seen to many hyd lifters stay pumped up solid for too long after engine shutdown and the valve is open with high spring pressure trying to bleed the lifter down.

If the cam you bought is a fast rate .904 lobe profile, it's may be noisier in general than what you're expecting.

This isn't to say you don't have two spongy lifters, I'm just saying I'd verify you can repeat the results before I took anything apart.