Hp gain with LS6 heads?
Tech Contributor
Joined: Mar 2003
Posts: 12,094
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Re: Hp gain with LS6 heads? (70 LS1)
15-20 hp depending on other mods. I used a thinner gasket when I put them on to pop up the CR to 11:1 another 5-7 for that. You can then port them when you get more money and there is no need to have them milled. The stock 02 springs and valves are good for cams in the .550-.560 lift area so you can get the 20-25 hp with no other mods. If you buy the bare castings then get manley race flow valves in the 2.02/1.57 sizes and get a 3 angle valve job done to put them in. The REV 1116 dual valvesprings come with new seals and hardened seats for 350. You will still have lots of room for improvement down the road with a port and polish from MTI or other good tuner. They would eventually be some of the best heads and you can buy them in stages.
