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Roller rocker arms and valve springs on an LS cylinder head at Grayless Automotive

Custom GM builds · LS and LT · Frankfort, Indiana

25YRS

Specced, built, degreed, then tuned in the same building.

Corvette · Camaro · CTS-V · Silverado · Sierra

01 / THE ARGUMENT

A cam is only as good as the calibration behind it

Plenty of shops will install parts. Fewer can pin an ECM, fewer still can tune what they built, and almost none can put it on a hub dyno afterwards to prove it. Doing all four in one building is the reason cars come here from Lafayette, South Bend and further.

01 — SPEC

Parts chosen for your combination

Cam, springs, pulley, injectors and fuel system picked together. A cam that fights the converter is a cam that costs you power.

Performance camshaft before an LS cam swap at Grayless Automotive

02 — BUILD

Degreed and assembled

Measured, not assumed. Clearances checked and documented so the tune has something honest to work with.

GM 6.2L timing cover open showing the oil pump and timing chain

03 — CALIBRATION

ECM pinning, where most shops tap out

Pinning, flashing and custom calibration on cars other shops send away. This is the capability that makes the rest of it possible.

Corvette with the LT4 supercharger removed during a build

04 — PROOF

On the hub before you leave

Baseline and final on the same equipment, same day. You get the sheet, not an estimate.

Car strapped to the Mainline ProHub hub dyno
02 / PLATFORMS

What we work on most

Late-model GM is the specialty, but the dyno and the tuning do not care what badge is on it.

C5 / C6 / C7 / C8

Corvette

Cam packages, blower and pulley work, supporting fuel, and calibration to match.

5th and 6th gen

Camaro / CTS-V

LSA and LT4 ported blowers, pulley upgrades, heat management, tuning.

LS and LT trucks

Silverado / Sierra

Cam swaps that still tow, AFM and lifter work, tuning for the way you actually drive it.

03 / START IT

Tell us what you are chasing

A number, a sound, or just more than it has. All three are a fine place to start.

Or call or text — (765) 357-4666