'08 Tahoe, LMG

Pertinent backstory:
AFM was tuned out a few years ago but a ticking lifter is getting worse so I'm taking that as a warning. Not wanting to invest any more than the bare minimum into this 5.3, I bought an L33 cam to avoid custom tuning costs. Well, I've decided to have the heads mildly worked over (mild shave and hand porting) since they'll be getting a clean-up pass and valve job anyway. I'm allowing this since the heads can be used on another motor or sold separately. With the modded heads, I'll be getting a tune for the bumped compression and extra CFM. Last night, I was offered a deal too good to pass on a TSP Stage 2 low lift truck cam. Good thing I've already added a tune to the budget!

Getting to the point and question:
I'd rather use thinner head gaskets for tighter quench rather than take it all off the heads. My current thoughts are to mill the heads to get the chambers to their advertised/blueprinted volume of 64cc since they're likely around 66cc. This should take around .012" to achieve. Then, for the gasket, the off-the-shelf ones look to be .040" installed thickness compared to the factory .051" Altogether, this would tighten everything up .023". From reading a few other's builds, it looks like these motors can handle a .030" head shave with 22x cam. So, I should be plenty fine with my 212/218 cam and ".023 shave", right?

Yes, I realize this would put me at or a little above 10.5 SCR (which I like) and I run 92-93 octane exclusively.

 

You will be fine.

 

For contrast, I daily a 370/706 head combo that runs about 12.5:1 and a CompCam 222/224, 93 octane and 22 degrees of timing.

 

Thanks guys. I know mine is a very mild build and didn't think I was entering any danger zones. For the past year, I had been planning a 100% stock refresh but without AFM and NO extras (it's not easy to hold back!) just to have a cheap but reliable 5.3 until I was ready for more cubes. Then, a deal fell into my lap which flipped the script to mild head work, cam and tune. I can't spare the extra downtime from switching up my game in the middle of a teardown, so I needed a little affirmation from the modded side before I take this unplanned (but very welcomed!) detour.


@madmann26 I bet that thing is peppy as hell! Have any vids? I love to hear high compression and big cubes popping

 

It’s very peppy. Even with the 80e and 3.90 rear, 1st and 2nd are useless if I push it from a dead stop.

 

Uh oh, now you're going to go faster than me! LOL

 

This is a 3rd gear pull at about 65% throttle.