Personal experience the xr274hr leaves a lot on the table with that setup... i had it in my silevrado with essentially the same engine and it was alright but the stage 2 ls3 cam from btr was a night and day difference.... my engine is an 04 lq4 bored .030 over with 823 heads, and stock intake, with truck injectors.

 

If you want low end the cam that was recommended would be a good all around cam.

On the head gaskets, get the LQ4 gaskets so that you have the right size for the bore size. A thinner gasket is up to you, they don't change a whole lot and they're pretty expensive compared to stock gaskets from what I've seen. And if your gonna boost it I would rather have the OE gaskets. The 9.7 or so compression you'll have is good, thinner gaskets won't change it much.

As for rockers, it's really hard to beat stock rockers. They're light, strong, have a good wipe pattern, and cheap. If I were you I would spec the cam the way I want it instead of spending several hundred dollars more on rockers to increase the cam size. Aftermarket rockers are also heavier so you need to consider your spring choice if the rocker you choose is heavier than the OE rocker.

 

 

 

I goofed before and said to get the LQ gaskets, if you're doing a L92 top end you'll need those gaskets so that the bore of the head isn't covered up. I believe that's a 4.080 gasket. (bore size 4.065 on the L92)

That cam is a decent size, you'll want a 3k or so converter for that.

I'd really recommend calling cam motion and discussing your build and goals to get the best cam recommendation