We've found the BTR .660" Dual Spring Kit to be the best performing valve spring on the market for these camshafts. There are a couple of different options:

Retainers: For applications spinning a high lift cam (SS1 or higher) 7,000rpm and beyond - the added valvetrain stability and lighter weight Titanium retainers are well worth the $70 upgrade in our opinion. For applications not spinning over 7,000rpm the Steel retainers are likely sufficient.

Locator Type: The default .505" Standard Size locators are for all OEM LS Guides. If your heads have been fitted with .550" bronze guides, choose the .565" Bronze Guide option.

The 7.425" pushrod length option is the correct pushrod length for "most" L99's (stock unmilled heads, stock undecked block, and stock thickness head gaskets). A stock L99 utilizes a 7.400" pushrod, but due to the smaller base circle of our camshafts, we recommend going with a 7.425" pushrod. This allows us to maintain the correct amount of preload.

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 7.425" to a 7.400" pushrod.
2) If you mill heads .040" and run a .040" gasket vs. the stock .051" gasket you'd want to run a 7.375" pushrod.

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

Includes timing cover, gasket, bolts, and sensor.

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 2110 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 LS3/L99 Head Gasket is the factory OEM replacement gasket for your L99 engine (.051" thickness). These are good for most NA head & cam builds that want to maintain stock compression.
2) The LS9 Head Gasket is the factory OEM replacement gasket for the LS9 (.051" thickness) and has more layers than the LS3/L99 gasket. These are great for most forced induction/nitrous builds that want to maintain stock compression.
3) The Cometic LS3/L99 .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. The L99 may require fly cutting intake valve reliefs to run a thinner gasket. (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 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 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 Chevrolet Performance bolt is completely adequate, but it is a torque to yield (one-time use) bolt. If you end up having to take your harmonic balancer back off, you will need to purchase another balancer bolt. If you don't want to deal with replacing the bolt after each replacement - you might consider upgrading to one of the higher quality options.

The Chevrolet Performance timing chain is completely adequate for most of our customers...

...but if you aren't happy with anything less than the highest quality product available - we are confidant in saying the Katech C5-R Timing Chain is the best quality timing chain on the market.

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!