Home / CNC Porting / LS & LT / 6-Bolt LSX — LS3-based
Chevrolet · LSX LS3 · Pair

6-Bolt LSX — LS3-based head porting.

Carma’s 6-bolt LSX program on the LS3 casting — 2.20″ valves, wider backcut, 412 cfm peak on our bench.

CNC ported in-house in Nashville Flow sheet with every set Ship them in or drop them off
$1,200per pair · both heads
BOOK THIS PORT — $1,200 CALL (615) 730-8654
Peak flow gain
+104 CFMat 0.700″ lift
Ported peak
407 CFM303 cfm stock
Price
$1,200per pair, CNC ported
Flow data

What this head actually flows.

LIFTSTOCKPORTED0.201551570.302222310.402722830.503053400.603143830.7030340701002003004000.200.300.400.500.600.70CFMvalve lift (in)
StockCarma CNC port

Intake flow at 28″ — stock and ported, both measured on our own SF-1020 flow bench.

+104 CFM at 0.700″ lift — 303 cfm stock to 407 cfm ported, the biggest single gain on this head.
The port work

What we do to it.

Our full-race take on the LS3 casting: CNC port, 2.20″ intake valves, and a wider backcut valve job — 407 cfm at .700 and a 412 cfm peak at .730 lift on our SF-1020 bench. Graphed against a stock LS3 on the same bench.

The spec

Fitment and pricing.

Engine
Chevrolet 6-Bolt LSX — LS3-based
Configuration
Pair (both heads)
Fits
6-bolt LSX blocks · big-power and boosted LS3-platform builds
Best paired with
Big cam, single/twin turbo or blower builds, forged bottom end.
Price
$1,200 per pair
Add-ons

Valve upgrades for this head.

Offered with the port work on this platform, fitted while the heads are apart.

Inconel Exhaust Valves (set of 8)Race-grade Inconel exhaust
+$263.12
Related

The rest of the combination.

Ship them in or drop them off.

Heads can come to us on a pallet or still on the car. Tell us the combination you are building and we will tell you honestly whether porting is the right next step for it.