will 6.0 heads fit on a 2001 5.3?

 

yes

 

They will fit, have bigger valves and flow better. They will also cut your compression. If you mill them .040" and use .041" thick head gaskets you can keep compression up to about 9.2 to 1. Your stock compression is 9.4 to 1.

 

ok, for the dumb person here, what will the 6.0 heads do for me. i am sure more power but what are we talking here? or is this something that is better for the gas?

 

if you drop a set of stock 6.0 heads on your motor, you'll see maybe 10-15rwhp due to the compression, but if you mill them to 5.3 compression, they will make a lot more power, they flow really good, and have bigger valves. you will see some good torque gains.

 

Wouldn't you lose hp with stock 6.0 heads since you would lose compression? Mill them back to down to 61cc from 70cc and you'll see gains.

 

you'll gain a bit i'm sure just dropping them on, but if you mill them to 5.3 compression then yeah, you're gonna gain more. i think the increased flow, and better port design would do more for power than the slightly lower compression ratio.