ProMaxx 3140 XXtreme 245 LS1/LS2 Cathedral 3.898 Small Bore 63cc Bare Heads

Fits Vehicle: LS1/LS2 Cathedral Port 3.898 Small Bore

SKU: 3140

The 245 cathedral head is the best of both worlds with the 11-degree valve angle and cathedral port shape. No cathedral head can come close. Independent dyno tests have shown an LS1 to produce over 490 horsepower to the wheel through a 4l60 transmission with factory manifold and cam on pump gas.

Features:

• LS 245cc Extreme Cathedral 3.898min 2.08/1.60 63cc Bare Pair
• Requires 3.898″ bore minimum and LS3 intake rocker
• Pro-designed ports & chambers
• 245cc as-cast port designed and tested in the USA
• Ultra-smooth 356-T6 Aluminum Casting
• 5-angle valve job
• 63CC or 59CC Chamber size or additional options available
• 11 Degree Valve Angle
• Diamond honed guides
• Built-in raised valve cover rail
• Monster .750 deck thickness
• Billet LS3 OEM Rocker Stand
• For use with standard or 6 bolt pattern
• Large spring pockets
• Utilizes 2.08 intake valve and 1.60 exhaust valve (Larger sizes available upon request)
• Multiple spring options
• Assemblies include: 21-4N stainless 1pc swirl polished back cut valves
• Machined and Assembled in the USA
• Outperforms other comparable heads in the industry
• Accessory brackets may require different bolts
• Sold in Pairs

Flow Chart

2.08/1.60

Cylinder Head Options

Technical Specs

Combustion Chamber ……53cc-66cc
Weight …………………………66 lbs.
Intake Runner ……………. 245cc
Exhaust Runner …………..
Intake Valve Size …………2.165”-2.200″
Exhaust Valve Size …….. 1.57″-1.60””
Spring Pressure

Hydraulic Roller .650 max lift

Closed …………………… 155 lbs. @ 1.800”-
Open …………………….. 425 lbs. @ 1.150”

Valve Guide ……………Manganese Bronze
Valve Seal Material … Viton
Retainer Material ……Titanium or Tool Steel
Valve Job ……………… 5-angle
Valve Spacing ………. OEM LS3
Valve Seats ……………Hardened Steel

Brand

ProMaxx