did you happen to check and see if you cut the oil pump oring when installing it?

 

I'm running the 7.350 pushrods with my cam and LS7 lifters, my preload is only around .030". Here's what my motor sounds like after all is said and done. I'm not worried. Of course it's going to make noise with a cam and headers. These lsx motors are just noisy in general. Even a stock one.

 

sounds good Joe!

 

The headers came with a full new bolt kit. I did throw out their cheap paper gaskets and went with a good stainless set. I've had a stethoscope all the way around the exhaust and haven't found any leaks.
I did see that a few people have mentioned really aggressive lobes (comp XER specifically) causing loud valve train issues that were resolved by getting a new grind of the similar specs on different lobes.

 

The bolts that come with the headers are crap! If you still have the stock hardware use it along with a set of stock exhaust manifold gaskets. There is too much noise there all be valvetrain.

 

I don't know about other people, but my valvetrain isn't audible outside the vehicle, but inside you can hear the valvetrain noise that is resonated by the headers. I run a 7.4 pushrod. To me, it sounds like not enough preload on the lifters instead of too much. Not enough will clack, too much will miss... in my experience anyway.

 

I'm not sure what else it could be, other than valve train noise. I've listened to the bottom end and feel it can't be coming from there. All I really hear is a gentle whirring noise that I would expect. I did also try unhooking each coil pack individually to see if it went away. It truly doesn't sound like anything on the bottom end, but figured I've been checking everything else...
I did check again for an exhaust leak, I'm not hearing anything that would allude to it. The noise is also very mechanical in nature and "bright" like you would expect with metal on metal contact. Exhaust leaks I've heard in the past have been much duller than I'm hearing here. I do think I have the factory engine side hardware for the old manifolds. I'll try to dig them out and replace as well.

This morning I did get a response from Roger, who designed the cam. He verified that it is on a stock base circle. Given the LS7 cup sits .050 higher in the lifter, only a small mill for cleanup, and a stock MLS gasket, I feel pretty confident that the 7.350's should work. I'm tempted to put them back in and swapping out the rockers with another stock set I have. IMO the 7.4's are too much preload.
I called up a local shop to see what their schedule was like. Sounds like they'd be at least a few weeks out so I have some more time to kill while racking my brain.

The whirring I can barely hear outside the vehicle. What concerns me is the slight knocking noise that develops around 1.5k RPM. I can easily hear it with the hood closed inside or outside of the truck. It would indicate something is loose, but I'm just not seeing it in my measurements.

 

I've been trading emails back and forth with Roger a bit this morning. He mentioned that I should try a 7.450 pushrod and that many of his customers use them. Even though I feel the preload is crazy high I'm considering it due to how the motor sounds. Before I drop another $100 on pushrods for something that might fix it, I wanted to get a consensus of what a few others think. With the 7.4's I don't believe I'm bottoming out the lifters. It idles very smooth and while I measured preload I did also measure valve movement at the retainer to insure it wasn't moving at all.

 

Do you know if different valves were used? Was the seat re-cut? I would first check the footprint of the rocker on the valve tip. If the footprint is not hitting in the middle of the tip, the valve tip is at the wrong location (this can be corrected by adjustable rockers, or shimming the rocker). I use a magic marker for this, you don't have to buy the compound. Are you certain that the rockers are not hitting the valve covers? I had to machine mine out quite a bit to get my comp cams rockers to fit (I know you are using stock ones). Does this noise sound like it is coming from an isolated location, or the whole bank? You can use the long extension in your ear trick. Mine makes a little noise too just so you know. Not as loud as yours, but it sin't as quiet as stock.

 

Yes, I do know they're larger than stock valves, however don't have any details other than they're 2.02 and 1.60. I'm assuming the intake valve is either a little longer than stock, or the valve seat is recessed in the head a small amount. With the same sized pushrod on both the intake and exhaust, the intake ends up with more preload. I hadn't really considered how this would effect the pattern.
I did attempt to check the wipe, however I was never able to make the sharpie wear off the valve tip. I'm assuming this could be because I was rotating the engine by hand using checking springs. I'm not certain how I would otherwise do this with hydraulic lifters. Would I let the motor run(to pump up the lifters), mark the valves, put it back together, then spin it over with the starter?
I had thought the rocker hitting the cover was a possibility, however the noise is still there with the valve cover off.