CNC Aluminum Cylinder Heads

Check out the newest generation of the Big Power aluminum cylinder head. The 3rd generation cylinder heads feature thicker castings and fully CNC ports and combustion chambers.

521HP / 627FT-LBS 540CID Build car craft 8.1L magazine article

Car Craft magazine put our 540 stage 1 truck kit in their 2006 Chevy Avalanche and made 521HP / 627FT-LBS with headers and stock exhaust!

540cid Chevrolet Avalanche Build
Intake Manifold Information & Installation

We've received so many calls about the intake manifolds for the 8.1L engines that we made a video. We've covered installation and general information about prototypes and production models. Larry explains the differences in gaskets and bolts from GM, which ones you should use and which ones you shouldn't.

8.1L Ceramic Spark Plug Wires Now Available! 8.1l l18 ceramic sprak plug wires

We've melted enough wires to know that standard silicone boots don't hold up to the heat your headers are putting out. Our new ceramic plug wires for both street and marine applications feature 45 degree boots rated to 2000°F!

8.1L Vortec Swap Resource Thread 8.1l l18 engine swap resource

CK5 Forum has an excellent 8.1L engine swap resource thread with great pictures and part numbers for those considering an L18 / 8.1L / 496 engine swap. Check out the 8.1L / 496 swap resource thread on CK5 here.

8.1L Swap Into 1969 Vette 8.1l engine swap into hot rod 69 corvette

Corvette Enthusiast magazine did an excellent job covering every nut and bolt of a 496/8.1L swap into a 1969 Corvette.
When all was said and done, the ’69 put out 359hp/475ft-lbs at the rear wheels with over 450 rear wheel ft-lbs available from 2,200rpm! All this from stock heads, a very mild 218/224 camshaft and roller rockers.
Check out the full build article here. (12MB)

raylar ported intake manifold dyno Modified Stock Intake Manifold Dyno Results

On stock iron cylinder heads, the modified stock intake manifold adds 20 peak horsepower, boosts low end torque and extends the overall powerband of the GEN7 big block.

540 Baseline Dyno Video

We put together a few of our favorite videos of the 540 Suburban so you can check out idle quality and performance output with the stock heads and the 203 camshaft / iron head spring kit. It's incredible how much the stock intake manifold chokes the engine above 3000RPM!
Stay tuned for a new video of the 540 Suburban with our modified stock intake manifold.

raylar prototype manifold New Intake Manifold Prototype

This is our dyno testing only prototype of the new Raylar 90mm intake manifold which will be a direct replacement piece and made entirely out of aluminum.

Roller Rocker / Valve Train Adjustment

Check out our 16 minute valve train installation video. Larry runs through the steps necessary to properly pre-load and final torque our stainless steel roller rockers.

6.0 - 9.0L Engine Swap Buildup

We'll be swapping a 6.0L in a 2003 Suburban 2500 to a 9.0L (547cid) stroker engine. This kit still retains the stock 496 block! To read more about it, check out our live blog at GM Fullsize forums. Our 4.75" 540 stroker kit / build pictures / dyno information will be available soon.

Performance Packages & Parts Videos

We've make some new videos to help explain (and show off) our performance packages and parts. We would like to thank our customers for sending us videos of their vehicles. Check our new videos out here.

Raylar Cool Gap Intake Manifold Options

We now offer the Raylar Cool Gap intake manifold in a variety of induction options depending on your airflow needs:

  • 78MM (3 bolt / LS1 style)
  • 80MM (Ported 3 bolt / LS1 style)
  • 90MM (4 bolt / LS2 style)
  • Unlimited Edition (Dual 1000CFM Carb-Plate EFI)
Raylar C5 Custom Short Runner Manifold

The new short-runner custom version of our Cool Gap intake manifold is installed on the Raylar C5 Corvette. We haven’t had a chance to really shake the new manifold down on a dyno yet, but seat-of-the-pants testing revealed the Vette will outrun a new Ferrari 458. Keep checking back as we add more to this video.

Stroker Crankshaft Kits

Raylar now has new forged stroker crankshafts in stock to increase the 496 engine up to 540/547cid with special forged pistons and connecting rods.

Desert Storm Boat Crash

While out at the 2013 Desert Storm Poker Run, we watched a spectacular boat accident. Thankfully, no one was hurt.

New Forced Induction Camshafts

Raylar now offers two camshafts for supercharger applications, the BP-207-S and BP-111-S. These camshafts have special valve event timing to maximize supercharger boost and efficiency.

Want Even More Power?

Vortec 8.1L Intake Manifold Modification

vortec 8.1l 496cid intake manifold porting Intake Manifold Modification - $1350

For trucks not requiring maximum high-RPM airflow, we can modify and port your stock 496 / 8.1 liter intake manifold. This intake modification will increase airflow to your engine, still retain stock looks and passes emissions. We remove the stock plenum blockages inside the manifold to reduce restriction and free up horsepower and smooth the individual intake runners. Intake manifold modification does not replace the Cool Gap manifold but does offer about 80% as much airflow. Intake manifold modification will show gains in the low to midrange RPM band.

Intake Manifold Video

How Much Air Do Raylar Heads Flow?

mercruiser aluminum cnc cylinder head overlay vortec cylinder head

Raylar Big Power cylinder heads out flow every 496 / 8.1L cylinder head on the market. Our combustion chambers promote a more even burn, increasing engine efficiency, fuel mileage, improving driveability and reducing detonation in forced induction applications. Check out the flow numbers for our standard Raylar CNC heads and our special-order CNC Extreme cylinder heads using the link below.

Cylinder Head Flow Comparison

Mercruiser 496cid Cast Pistons Break

stock vortec mercruiser piston damage

The stock 496 / 8.1L cast pistons are not designed to withstand the forces of extreme endurance use. We routinely see engines with cracked, chipped and even shattered pistons which result in catastrophic engine damage.