ProMaxx 3161A XXtreme 260 LS3 Rectangle Large Bore 63cc Hydraulic Roller .650 Heads

Name: ProMaxx 3161A XXtreme 260 LS3 Rectangle Large Bore 63cc Hydraulic Roller .650 Heads
SKU: 3161A
Price: 2340.99 USD
Availability: InStock

Fits Vehicle: LS3

SKU: 3161A

The XXTREME LS 260 is the big boy on the block for as-cast LS Head technology. This head is for large bore power. Dyno results produce 700 HP plus on pump gas.

Features:

260cc LS3 2.165/1.60 63cc Associated Spring Pair
Pro-designed ports & chambers
260cc as-cast port designed and tested in the USA
Ultra-smooth 356-T6 Aluminum Casting
5 angle valve job
63CC 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 2.165 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

2.165/1.60

Flow Data @ 28″ water
lift	200	300	400	500	600	700	800
Int	147	225	280	335	362	375	376
Ext	60	115	180	215	230	245	252

Cylinder Head Options

Part No	Description	Valve Sizes	Chamber Volume	Max Lift
3160	260 LS XXTREME 3/2/1 Bare	2.165/1.60	63cc
3161A	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	63c	.650
3161P	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	63cc	.650
3162	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	63cc	.650
3163	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	63cc	.700
3164	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	63cc	.800

Part No	Description	Valve Sizes	Chamber Volume	Max Lift
3165	260 LS XXTREME 3/2/1 Bare	2.165/1.60	59cc
3166A	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	59cc	.650
3166P	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	59cc	.650
3167	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	59cc	.650
3168	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	59cc	.700
3169	260 LS XXTREME 3/2/1 Assembly	2.165/1.60	59cc	.800

Technical Specs

Combustion Chamber ……53cc-66cc
Weight …………………………66 lbs.
Intake Runner ……………. 260cc
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

Spark Plug…………….NGK R5671A-7 3/4 GASKET SEAT PLUG