Drawbacks using Ls9 heads?

[ICUP]

Was originally going with TMS for my build, but their prices has skyrocketed. The shop I'm going through spec'd out the same thing just using Ls9 heads compared to M311 heads. Saves me about 3500-4K also.


Any drawbacks, or power will be the same output?

[blake-b]

In the ZR1 world, Ported LS9 heads are making the same power as aftermarket heads. For a ZR1, the only reason to go to an aftermarket head is for a 6 bolt set up.

I don't see any drawbacks.

For the record, I am running a set of AFR 260 heads ported by Tony Mamo. I wish I had known about the lack of power gains vs stock ported heads and kept the LS9 heads.

[JMI]

The LS9 has a better material, but they flow less than a LS3 stock vs stock from what I've seen.But if you have them ported or CNC's.,then it's a difference story.

[Batmanntexas]

For a boosted application, the LS9 has my vote. Port those babies and let 'er eat!!

[ZL1C7]

I have a set of Katech CNC ported LS9 heads. I also have a new set of M311's and a set of PRC LS3 heads. Let me know if you need more info about any of these.

[ICUP]

I'm not planning on running huge power, but the shop I'm going through has used ls9 heads on some of their 1500hp builds.

[4SFED6.0]

Im running a set of gmpp cnc'd ls9 heads and am very happy with them. With the ls9 block im able to take advantage of the 12mm head studs. The block used to be the same price as an ls3 but I believe its now been discontinued. Im sure there are comparable or better aftermarket heads out there but I wanted to keep it all ls9.