Thinking of doing a head-swap on my Trailblazer-SS. Stock it has the 243 heads. How much HP improvement would you guess it'd get by swapping out the stock 243 heads for a set of PRC or Livernois ported 243 heads? Cam would remain stock, which is basically the '01 LS6 camshaft.

I don't want to swap out cams due to warranty purposes. I figure that the only way the dealer would find out about the ported heads is if there was a catastrophic engine failure requiring a teardown, which the LS1/6/2 has already proven itself to be very robust. Thus, an engine failure is unlikely. For the ported cost of the PRC-243 heads, minus the resale value of my stock 243 heads, it seems like it'd be a fairly good bang for the buck.

Thoughts?

 

20>30 rwhp, tuning required.

 

How big (or small, actually) of an intake runner should I try to keep/find, knowing that the heads would be going on essentially a stock LS2 motor w/ a slight variant of the '01 LS6 camshaft?

Methinks a big runner (ie, 237cc) would kill my low-end, esp in a 4600# SUV.... (??)

 

Just about every company mills their logo on the front of the head. You need to request that they not do that. Also you need to do it soon so the surface of the heads age with the rest of the engine bay. Example, when I put heads on my car I will not be able to hide it.

 

Good tips; will definitely have to request "no-logo". But its an 06 with only 2k miles, so I doubt I have to worry about any "aging" just yet. Heck, nothing a little road-dust on the first couple trips won't coat.

 

I'd also say around 15-20whp through an AWD...that with fixing the garbage stock tune that I hear those things come with it should move pretty good.