Yeah if I was you I'd probably get used to that noise. All the rockers sold for the 3.8/4.2 are all based off the 351C rockers and of of the wrong geometry for the engine (arent yah glad they told yah that when yah bought em!)
Anywho,, I to am one of the ones who was fooled so dont feel bad.. its kinda the reason I'm on a crusade to find a better rocker.
If you are using a reground cam and those rockers the pushrod legnth is most likely wrong.
what you want to do is get the rocker tip to move as lil as possible threw rest and full lift positions. this of course takes time and trial and error.
What you need is a adjustable pushrod and a series of shims.
Comp Cams makes roller rockers specifically designed for the 3.8 now. The market is improving. I have the Harland Sharp roller rockers, which were one of the first on the market. I havent had any problems with them at all. But if you're using a reground cam you will need longer pushrods. Adjustable pushrods are meant for measurement purposes only. I had to get mine off Summit because everyone around here carries Chevy length adjustable rods. And you can buy custom length pushrods off of Summit also. But if your cam was reground you wont need shims, you'll need longer pushrods.
1988 Notch Mustang: - 438W, direct port n2o, t56 2003 SVT Focus: - SCT X3 tuner
What I'm trying to say is that each reground cam has different measurments (duration/lift/etc) so if they reground a 207/215 cam off a stock cam then they remove a certain amount of material to achieve that...but if they ground a 224/232 then they have to remove more material.
there is no magical number that fixes all... pushrod legnth is a science/art so to speak. each motor is individual unless its a production motor then they machine everything the same.
You need to be able to mark the tip of the valve with a permanent marker and what your trying to achieve is the least amount of travel of the rocker accross the valve tip.
This saves the rocker from undo side loading and causing the valve guide to wear prematurely.
do a search on Google for ROCKER GEOMETRY and start readin