what would the valve stem look like if I where getting into valve float I have lost .4 and 4-5 mph in the 1/8 I just run a comp test and a leak down test and found no problems there no more than 3% leakage

not sure but you should hear valve float??
flat tappet cam??
torque converter?

solid roller lash has not changed converter only has about 25 passes motor sounds no different.

Valve float, unless its really major float is pretty hard to hear, We chased a valve float problem < so I thought > the year before last and found it to be a undersized needle and seat orifice in the rear bowl, well hell we could have used new springs in another 500 passes any how, I don't know of a way of checking by the valve stem, unless its loose in the guide,

I hear nothing but I have a few stems that have an odd looking pattern on the tip

Valve float hammers the locks and retainers. Remove a few springs and check the lock OD and retainer ID for signs of trouble,you may also find the retainers difficult to remove.

I had a similar problem some years ago, checked everything, found nothing, until I put in new plug wires...

plug wires are MSD and only have about 50 passes on them

If it's happened all the sudden, you should be able to see it in the valve spring pressures...

On those heads the valves shouldn't rotate much beyond their initial assembly. If you notice multiple (and by multiple, I mean more than two) roller patterns on the valve tip, this usually means it's floating. What cam, lifters and rpm are you running?

Erson solid roller 246/254@50 592 lift Crane lifters 65-6800

There are SpinTron vids around showing the entire spring pack (bottom cup and all 3 springs) jumping right off the head and squeezing together in the middle.

Can't sleep after watching that.

Unless the spring has a rotator, the valve shouldn't rotate if the spring is doing it's job in keeping the valve under control. I've seen that video you're talking about but that's extreme RPM and showing what happens to the valve spring under those conditions. I've pulled tons of heads apart and only see two roller patterns on the tip of the valves. The first from when the engine was first started, and the second, after the spring rotated the valve a bit and the valve settled into it's position.

Oh and to answer your question, the spring, keepers and retainer are what keeps the valve from rotating. Unless it's a multi groove, then they'll spin as the grooves keep the retainer located and not the press on the valve stem as in a single groove setup.

It's not the high speed...

http://www.youtube.com/watch?v=019Jyn9oB5k

Interesting though, I've seen some that rotate, and some that don't.

In general it seems like the larger springs with an opposite wound inner spring rotate less vs. the single spring stuff.

I can't see that it's related to valve float though because I found some really nasty valve float videos that didn't rotate, as well as some clean low RPM stuff that did rotate...

VALVES "generally" (when everything is right) don't rotate.

Float/spring surge/harmonics will allow them to move around some, giving the crazy looking roller tip wear patterns you occasionally see. Otherwise you almost always just see straight across uniform single wear pattern on the tip & can see the valve has been sitting in same position it's entire running life...... Also when you find a valve that has tremendous stem wear (often see it in high offset rocker ratio heads) The wear is perfectly consistent (I know I'm not describing that right but) I just disassembled some W5's off a +.675" offset rocker motor few months ago that had alot of run time & some of intake stems were worn as much as .002", & they wore in one spot as valve was consistently sitting in same area being side loaded the same for pass after pass.

I'm not going to get into a tech discussion about why/why not, but I agree, anyone who has disassembled any # of heads & looked @ wear patterns knows they don't.

I understand offset rockers undergo extreme side loading themselves
but, don't see any possible way a pushrod/rocker arm can transfer
any side load to the valve stem.

Prolonged intervals in tear-downs might result in stem wear perpendicular
to the rocker shaft but, I can't envision the side loading.

I'd be interested in the tech discussion.

I agree - there are reliable reports of local wear, but exactly how does this happen? Is the long lever bending sideways as it depresses the stem?