92whitelightning

haha...yea thats it...if the "dog bones" keep the lifter in place right....and like i said there is a gap between the lifter and dogbone, big enough so that the lifter isnt even touching the dog bone when there are tightend down all the way...THE LIFTER IS TO LOW TO TOUCH THE DOG BONE....SO WHEN THE LIFTER RAISES IT HAMMERS AGAINST THE DOG BONE DUE TO THE GAP BETWEEN THE TOO...

67mustang302

Are you sure they're the right lifters? Sounds like you may have ate the cam lobe down, that's the only thing I can think of that'd make sense. And yeah, if 5,800 was too much you have crap springs. I'm running the Comp behives on mine and have had it out to 6,700 without any problems at all. But it's also not a huge cam, but not tiny either.

cleanfitty

Which 2 lifters??

92whitelightning

well the reason i only shift at 5400 ish is becuase i have a smaller pulley on the blower and that over revs the blower if i go higher then 5500 so i try to be safe...but on piston number 5 second farthest from the firewall and on piston number 3 the first one closest to the firewall....but there was no metal shavvings or anything in the oil and looking at the cam through the lifter ports it looks fine, nice and smooth....the only thing that i think that i am going to have to do it pull the cam out and make sure that they sent me a hydrolic roller cam instead of a flat tappet cam...its known to happen...especially when i ordered fuel rails from this mustang catalog and they sent me two wrong sided ones