I have adjusted the valves cold, hot and hot running. Have a great idle But at 3000 rpm sounds like every valve is clattering. 67 289 installed comp cam lifter (one of witch collapsed at first run in). New springs and keepers. Hard to crank after I run it down the road heat gauge not in hot area and laser temp gun showing 150.8
What is happening here. 
Ralph
What else did you change?
Timing chain, new Torquer 2 intake thats it. New water pump. Now the distributor vacume pot is right up on the thermostat housing. Hummmm
Well pulled pass side valve cover and number 3 rockers very loose, adjusted again 5th time number 4 intake valve not moving no amount of adjustment will move it.
I have already replaced #4 lifter and a pushrod. Are these comp lifters just that bad. No problems on driver side. Need help here plz
it sounds like the cam lobe flattened during brake in. take the lifter out and try to look at the cam . if the new lifter is good its a cam issue did you use cam lube and break in the cam correctly. also did you change the rocker arm nuts they should be changed could be why they are backing off.
Well the cam is worn almost no lobes on 3,4 and #8 were the same. Eat up the lifters also. Yes used cam and lifter lube also 10w30 valvaline racing oil with higher zink in it.
I cannot belive the cam is shot after less than 100.mile. anyway have contacted Jeggs an the are sending me a cam and lifter from a different manufacturer. Had comp in now going with Laramie. Spell ck no help here.
Be safe, Ralph
Easy to wipe a lobe on beak in…for years I have used Cam Research and have had them break in the cam and lifters in advance….
What are you going to do about all the ground up metal that has been circulated throughout the engine? 
Well I will flush as much out as I can with desiel and oil then crank her up for About 5 min an change the oil an filter again to clear the passages. Hope this will get the majority of it. Thanks for the replies, Ralph
Ok folks installed new cam from jegs along with new lifters. All I could get was major backfire. Called the manufacturer an gave them the part #. He laughed an said they sent you a 351 cam for your 289 so I must use the 351 firing order!!. So redid the plug wires on dist an bang she fired up, ran for 30 minutes at 2000 to 2500 rpm to runin cam an lifters. Temp gauge got real close to over temp but not on it. After shutdown engine would not crank acted like it had overheated dragged down battery. So now what??? Thanks. Ralph
PS prior owner did not run a t stat maybe that could be it??
The whole industry has been having issues with shortage as well as fast tracked parts. Lifter in particular are new but junk. No heat treatment, don’t pump up etc… Sounds like you have been caught up in that mess.
Yes that is it. Taking down the motor multiple times has taken a toll m on my back!! The amount of gasket kits has gotten old also. Hopefully this cam will run out for awhile. Thanks, Ralph
" After shutdown engine would not crank acted like it had overheated dragged down battery. So now what??? Thanks. Ralph "
Ralph, could be timing is a little to advanced, that is what happens with my drag car when hot.