what would be the difference in the power if i want to put 241 heads with ls6 (yellow) springs in a 5.3??????... the motor is stock but i already have some parts ready to install as well such as CAI LT's and a tune..

 

Probably not much since all vortec heads flow quite well. Your big concern like me is Bore size limiting absolute flow.

I would try upgrading your cam along with roller rockers along with those heads to take away a real advantage. From what I read roller rockers will give you the HP increase as the heads. Do all 3 with a good exhaust port job, and you might have something there.

But I'm saving for the roller rockers since they give me easy HP boost "up to 25", save my oil a bit compared to stamped rockers "friction reduction", and can even give a tad back in fuel economy since they require less power to roll over.