The Texas Speed Steel Adjustable Cathedral 1.8 Ratio Roller Rocker Package is a complete set of adjustable roller rockers for LS engines running cathedral-port cylinder heads. The rockers are machined from 17-4 stainless steel, use a swedged roller pin for durability and mount to the factory rocker pedestals, so they install without a shaft-mount conversion.
The 1.8 ratio raises valve lift and effective duration over the stock 1.7 ratio for a given camshaft lobe, and the adjusters allow lash to be set, which is why Texas Speed recommends this package for solid roller camshaft applications. The rockers are Spintron tested in-house. Stock valve covers are not compatible with the taller adjustable design, so TSP tall valve covers are required, and minor cylinder head trimming may be needed depending on casting variation.
Specifications
- Rocker ratio: 1.8:1
- Type: Adjustable roller rocker arms, bolt to factory pedestals
- Material: 17-4 stainless steel
- Roller pin: Swedged for improved durability
- Fitment: GM LS 5.3L cathedral-port cylinder heads, LS1 and LS6
- Recommended use: Solid roller camshaft applications
- Testing: Spintron tested in-house by Texas Speed
- Quantity: Sold as a complete set
- Valve covers: TSP tall valve covers required; stock covers not compatible
Note: Requires TSP tall valve covers; stock valve covers are not compatible.
Note: Minor cylinder head trimming may be required depending on casting variation.
Note: Verify valve cover and cylinder head clearance before installation.
FAQ
Which cylinder heads do the Texas Speed 1.8 adjustable cathedral rockers fit?
Texas Speed lists this adjustable 1.8 ratio roller rocker package for GM LS cathedral-port cylinder heads, including LS1, LS6 and 5.3L cathedral-port heads, mounting to the factory rocker pedestals.
What does a 1.8 rocker ratio do compared with the stock 1.7?
A 1.8 ratio multiplies cam lobe lift by 1.8 instead of 1.7, so valve lift and effective duration increase for the same camshaft. Spring travel, retainer-to-seal and piston-to-valve clearance should be rechecked with the higher ratio.
Do these rockers require special valve covers?
Yes. Texas Speed requires its TSP tall valve covers with this adjustable rocker package, since stock valve covers are not compatible with the taller adjuster design.
Are the 1.8 adjustable rockers meant for solid roller cams?
Texas Speed recommends them for solid roller camshaft applications, where the adjuster is used to set valve lash. They are built from 17-4 stainless steel with a swedged roller pin and are Spintron tested in-house.
Will I need to modify the cylinder heads?
Minor cylinder head trimming may be required depending on casting variation. Texas Speed advises checking valve cover and cylinder head clearance before installation.
