Considering the following mods for a little more RPM. Depending on how accurate my tach is, my motor breaks up at 5700-5800+. Only hit it flat out like this once or twice fora split second, but it is unmistakeable. - valve float. Springs that come on the ZZ502 heads seem like a perfect match for the hyd roller that I have [233/236, .600/.610]. Installed by GM at 140#@1.94" ht, 368# rate, netting 140/361 int, 140/365 exh. Leaning to .030 shim for 151/372 int, 151/375 exh, and going with titanium retainers. I do have a steel core cam so not worried about cam lobe wear.

Have also considered going to the 26120 Beehive, but Comp lists these as .594" max lift for spec'd installed ht of 1.88". I could install the 26120's at 1.91 and drop the seat/open to 144/366-368 (int-exh). By the time I add in springs, retainers, spring locators, etc., especially if I also go with titanium retainers on the beehives, I am in close to $600.00 for a spring change. I am not looking for 6400-6500 RPM out of this motor, just want a solid 6000 RPM out of it with a safety margin of a couple hundred RPM. Anyone else dealt with this and found a simple solution?

Dont think ou need beehives to go 6000, a regular double spring will do fine.
But if you do the beehives - no need for titanium retainers.

If you have the OEM lifters they could be a problem. E-mail Wolfplace and get a set of Morels. In back to back dyno testing by several engine builders the Morels have proven themselves to be 400 to 600 rpm better then other hyd roller lifters.

The heads are on a MRK IV, 454-030 motor. Lifters are Comp 854's. Heads were new out of the box when installed, the springs probably do not have 20 miles on them.

I shimmed my ZZ502 heads (0.060" I think) to increase the seat and open pressure when I installed my Crane cam. It floated the valves at about 61-6200 (if my tach and shift light were correct). I think the shimming may help a little, but it may not be enough for you.

Sure its float? When I run mine up to redline it just seems to run out of steam - no sputtering or popping.

Oh, mine was float all right. The motor flattened out power-wise and got pretty loud (valvetrain noise). When I changed out the springs for my solid roller, the retainers/locks were a pita to get apart. It looked like the locks had actually galled the retainers. I hear this is another indicator that the valves were floating. I'm glad I had quite a bit of piston to valve clearance, or it could have been worse. Solid roller = no more float now :)

Only happened a couple of times - when I was (um-cough cough) really laying into it and the tires just let loose like I was driving on ice. I got that distinct breaking up / misfire. Vince if you recall, when we took it out last week, I let off of it real early, only ran it to about 5000. Trust me, there is a whole lot more power the other side of 5000. I tend to think that with the 11/32" valves, another 12-15# seat and more lightening with titanium retainers may do the trick.

I think the Ti retainers helped my situation. I have a nice top-end surge now (the rpm intake may of helped also). I have 3/8 valves so my situation should be worse than yours. The Ti retainers are about half the weight of the steel ones that were on there. I had the same problem as Tom did w/the lock/retainers. There musta been so much float with mine that when I tried to get the valves out, they got hung-up on the guide. Where the lock recess was on the valve stem slightly mushroomed. I had to take a file and go around each stem to knock the bur off. Retainers and locks musta been moving around a whole bunch. I was surprised to see how much slop there was using the OE lock and retainers. The Comp Ti retainers and 10° locks fit real nice and snug. Looks like the Ti retainers have doubled in price recently.

You should be able to do the beehives for 300.00 without ti retainers,
which I did, huge difference in rpm ability, and I have just a "slightly" bigger cam. I would recommend them.

HI i got beehives in my zz454 with comp hyd roller huge diff ,6500 no problem and less valve train strain with these COMP beehives you win all round ,go for it you wont regreet usings these on a big block hyd roller setup
cheers victtor

Boy I wish I coulda ran them 'hives. Too much seat pressure for me though (155lbs @ 1.88), bled lifters down.