GPI – LT1 Cam Kit for 6th Gen Camaro SS / C7 Corvette

Valve spring selection is critical to valve-train stability and safe RPM tolerance.

• BTR 660 springs are an excellent choice for combinations with hollow stem LT1 intake valves up to 7,250rpm.
• The GPI 1209X springs are appropriate for combinations with hollow stem LT1 intake valves up to 7,850rpm and up to 8,200rpm with LT4 Titanium intake valves.
• The GPI 1513ML springs are our preferred spring for top quality and maximum longevity and are appropriate for combinations with hollow stem LT1 intake valves up to 7,700rpm and up to 8,000rpm with LT4 Titanium intake valves

The 7.850" pushrod length option is the correct pushrod length for "most" LT1's (stock unmilled heads, stock undecked block, and stock thickness head gaskets).

Anything you do to move the tip of the rocker arm closer to the cam lobe has to be compensated for by the pushrod. When milling heads, decking block, or running thinner than stock .051" head gaskets - you will want to run an equally shorter pushrod.

Examples:
1) If you mill your heads .025" - you should drop from 7.850" to a 7.825" pushrod.
2) If you mill heads .040" and run a .040" gasket vs. the stock .051" gasket you'd want to run a 7.800" pushrod.

We always recommend checking for proper pushrod length and lifter preload!

Camshaft that maintain variable valve timing (VVT) offer us the unique opportunity to advance timing at lower RPM's (to optimize low-end torque), and retard timing at higher RPM's. These phaser limiter kits give us the ability to optimize valve events in both scenarios most effectively based on the cam you choose.

We recommend the 0° Phaser Limiter Kit with all of our LT1 camshafts.

Due to the increase fuel lobe on our Gen V LT1 camshafts, high pressure fuel pump lash caps are required.

We have several lifter options to choose from.

Good. Our entry-level option would be to just replace the (8) AFM lifters with a set of (8) OEM LS7 lifters. These LS7 lifters are stamped out by the millions and are a very popular option. If you have some miles on your engine, there is also an option to purchase a full set of (16) LS7 lifters. This is a good option up to around 7,000rpm. We also offer a Cam Motion branded equivalent to the OE LS7 lifters available.

Better. The next option is to upgrade to a higher quality lifter. We offer the GM Performance Racing Lifter which is built with tighter tolerances than the LS7 lifter, has lighter internal mass and has been tested by GM to be reliable up to 8,000rpm. (this is our recommended lifter for most customers)

Best. Our final option is for the individual who is wanting to spin their motor freely without worrying about lifter failure. The Johnson 2110R lifter is built to the highest tolerances and is happy to spin beyond 8,000rpm. If you are after power and reliability - this is your lifter. GM repeatedly tested this Johnson lifter past 8,500 RPM, and is currently using them in the COPO Camaro's.

We offer several head gasket options. Many considerations must be made to determine the correct head gasket for your build.

- Do you intend to (or are you currently running a forced induction/nitrous setup)?
- If increasing compression will you have proper piston to valve clearance?
- If increasing compression do you have access to a high octane fuel to run safely?
- If increasing compression have you chosen the correct length pushrod?

We will try to answer these questions generally, but please note - these are general answers. If you have specific questions - feel free to ask!

1) The LT1 Head Gasket is the factory OEM replacement gasket for your LT1 engine (.052" thickness). These are good for most NA head & cam builds that want to maintain stock compression.
2) The LT4 Head Gasket is the factory OEM replacement gasket for the LT4 (.052" thickness), and has more layers than the LT1 gasket. These are great for most forced induction/nitrous builds that want to maintain stock compression.
3) The Cometic Gen 5 LT .040" Head Gasket is an upgraded quality gasket that is a great choice for a variety of builds (including forced induction/nitrous) that are also wanting a small bump in compression. With unmilled heads, this gasket works great with SS1-SS2 camshafts. May require flycutting for the SS3 or higher. (We always encourage measuring PTV clearance when running aftermarket gaskets with an aggressive camshaft.)
4) The Cometic Gen 5 LT .028" Head Gasket is an upgraded quality gasket that is a great choice for a variety of builds (including forced induction/nitrous) that are also wanting an even larger bump in compression. (We always encourage measuring PTV clearance when running aftermarket gaskets with an aggressive camshaft.)

Good. The Chevrolet Performance Head Bolts are adequate for most NA setups, but they are torque to yield (one time use) bolts.

Better. The ARP Head Bolt Kit offers much higher quality hardware and is torque to spec (can be reused over and over).

Best. The ARP Head Stud Kit is the best overall solution. The stud kid eliminates the wearing of threads in your block, offers the most accurate torque measurements, and offers increased clamping force. If you are utilizing any sort of forced induction or nitrous (or just want the best overall solution) - this is our recommended kit.

We offer two solutions for deleting AFM / DoD from your Gen 5 LT Engines.

1) The CBI Streetcars DoD Block Off's are perfectly functional and are a great value.
2) If you prefer a more aesthetically pleasing solution - Katech gives you some bonus style points with their beautifully finished AFM Delete Valley Cover.

The crank bolt is a torque to yield (one-time use) bolt and should be replaced after each use.

The lifter trays are plastic and hold the lifter straight. If the lifter turns it would wipe a cam lobe quickly and cause a complete teardown. Replacing these trays is cheap insurance.

The Camshaft Sprocket Bolt is a torque to yield (one-time use) bolt. GM recommends replacing after each use.

We recommend upgrading to the Fast Fish Front Timing cover as it incorporates a PTFE (Teflon) low friction lining. This is a premium quality racing seal and substantially lowers drag while maintaining oil control. Because of the small price difference - it is our default Timing Cover Seal on nearly all Shop Builds.

The Smith Brothers is a press in bushing design, which DOES requires special tools for installation.

The CHE is a full floating bushing design, and DOES NOT require any special tools.

The CHE is the superior bushing in our opinion, and is our recommendation if you plan to upgrade.

Buying a GPI Cam, and want it tuned by the team who designed the cam? Considered one of our tuning options.

We offer (2) Remote Tuning options. (Click Here to Learn More about Remote Tuning)

1. If you already own HP Tuners or EFI Live hardware - you can choose the Remote Tune Calibration Package (Requires HP Tuners / EFI Live). A new option will appear below that allows you to purchase HP Tuner MPVI3 Hardware. Just leave it on the default selection of "No HP Tuners MPVI3 Hardware".
2. If you want a remote tune and don't own HP Tuners or EFI Live hardware, select the Remote Tune Calibration Package (Requires HP Tuners / EFI Live). A new option will appear below that will allow you to purchase the recommended HP Tuners MPVI3 Hardware.

We also offer (2) In-House tuning options. (If you are local to us or want to make the trip to see us):
1. Street Tuning
2. Dyno Tuning
Both of these options get your car dialed in perfectly - although by selecting the dyno tune option - you'll get the additional bragging rights of the dyno sheet to know exactly how much power and torque your engine made!