I have the TR224 and 918's with 7.4 pushrods and no noise. It sounds stock other than the lope.

 

I have had the 918s and now I have the DART springs and they both sound the same. It is actually a possibility for the lifter to come off the cam and not damamge the lobe. When I had my comp pro mag rockers a few of the studs backed out due to not using loc tite and you could fit a .23 feeler gauge between the roller of the rocker and the valve stem but when I pulled the cam later on there was no visable damage to the cam and is now running in a member on this sites truck just fine. I truely beleive the sound is from the change in base circle of the cam which causes the noise due to using the same length pushrod even though the heel of the lobe is now further away from the rocker cup. Just my .02

 

I'm running the 226 226 585 585 112 with no sewing mechine noise oh yeah and running 7.4 rods now, might have some 7.425 rods for sale shortly.

 

some of the sound comes from wrong pre-load too. check over on ls1tech and do a search for Predator-Z. He knows his **** when it comes to this stuff. 7.4s work and are for the most part damn close for proper preload, but sometimes you need that .025 extra=7.425 for the proper preload. You can only accuratly get that buy measureing it with the proper tools.

Ski

 

What kind of tools can you use

 

Ever since my GT2-3 swap, I've got a nice loud sewing machine too. I know of a lot of others with this cam and LS6 springs like mine, and they sound stock. If there was a sure fire way to rid the noise I would do it in a heart beat.

 

if im not mistaken we should have .015" lifter preload.

 

my 918's are in there sewing some **** everyday

 

I wonder why some guy at Thunder Racing (in Baton Rouge) and Allen Nelson said that sound is normal. Actualy, Allen said that is common to have louder valve train noise from a cam swap.

Some day I may change to 7.425" harden push rods and see.

 

How can you be sure that you have the proper preload?