Are the comp type R lsx lifters different in their length or design that warrants a different pushrod length in an vs say my stock lq4 lifters?

Are these more for reliability or will they actaully improve performance on a sub 7k daily driven car..

Thanks a bunch!

 

Read the fine print on these from Comp. Preload is 0.002"-0.004" and they require adjustable rockers.

 

This guy hit the nail on the head! While you might be able to run your current pushrods, you will need adjustable rockers to get your oreload setup properly!