Edelbrock 61949 Installation Instructions
©2008 Edelbrock Corporation
Brochure #63-0414
Catalog #61949, 61969, 61979, 61989
Rev. 12/08 - AJ/mc
Page 1 of 2
PERFORMER RPM G.M. GEN III (LS SERIES) CYLINDER HEADS
For Gen III and Gen IV Small-Block Chevrolet V8s
Catalog #61949, 61969, 61979 & 61989
INSTALLATION INSTRUCTIONS
PLEASE study these instructions carefully before beginning this installation. Most installations can be accomplished with common tools and
procedures. However, you should be familiar with and comfortable working on your vehicle. If you do not feel comfortable performing this installation,
it is recommended to have the installation completed by a qualified mechanic. If you have any questions, please call our Technical Hotline at:
1-800-416-8628, 7:00 am - 5:00 pm, Pacific Standard Time, Monday through Friday or e-mail us at edelbrock@edelbrock.com.
IMPORTANT NOTE: Proper installation is the responsibility of the installer. Improper installation
will void your warranty and may result in poor performance and engine or vehicle damage.
®
DESCRIPTION: Performer RPM Gen III cylinder heads are designed for
1997 and later 5.7L LS series engines, and other third and fourth
generation small-block Chevrolet V8 engines. These heads provide great
“out-of-the-box” performance and feature CNC-ported, 205cc intake
and 82cc exhaust ports for superior flow, and efficient 65cc CNC profiled
combustion chambers. CNC-ported cylinder heads #61969 & 61979 are
designed for engines with 3.900” or larger bore diameters and will not
fit 4.8L and 5.3L engines with factory 3.780” cylinder bores. Performer
RPM Gen III cylinder heads can also be used on larger displacement Gen
III and Gen IV small block V8 engines including 7.0L (427 c.i.d.) engines
with 4.125” or larger cylinder bores using the C5R block, LS7 block, or
sleeved production blocks.
Partial CNC cylinder heads #61949 provide an economical alternative to
complete CNC ported cylinder heads, featuring as cast, 214cc intake
ports, partial CNC ported 80cc exhaust ports, and fully CNC profiled 65cc
combustion chambers.
As-cast cylinder heads #61989 can be finished to accommodate a
smaller bore size. This would be determined by the professional cylinder
head porting shop performing the finish machine work (See note below).
All heads feature reinforced rocker arm bosses for increased strength.
Complete heads are assembled with the following components:
❑ High quality, stainless steel, one-piece, 2.02” intake and 1.57”
exhaust valves for increased flow
❑ 2-ring positive oil control seals
❑ Valve springs accept camshafts with up to .650” lift
❑ Titanium valve spring retainers (Steel on 61949)
❑ Hardened valve seats compatible with unleaded fuel
NOTE: Complete cylinder heads are assembled and prepared for
installation right out of the box. Bare cylinder head #61979 will
have valve guides and seats installed, but will require final
sizing and a valve job to match the valves you will be using.
Small-port, bare cylinder head #61989 requires professional
preparation. This is a machined casting from which the
finished heads are made. The small, as-cast ports and
chambers are designed to allow a variety of designs to
completely clean up when CNC-ported. Follow the finisher’s
recommendations regarding maximum valve lift, gaskets,
and additional hardware, as cylinder head setup will vary
depending on the specific cylinder head assembly.
IMPORTANT NOTES, READ BEFORE BEGINNING INSTALLATION!:
For a successful installation, the Edelbrock Performer RPM Cylinder
Heads require some components other than original equipment parts. To
complete your installation, you will need the following items:
❑ Head gaskets (graphite); Right - GM #12558809, Left - GM
#12558810.
Or, multi-layer steel shim (MLS) gaskets, GM
#12498544 (both sides) may also be used. NOTE: Stock 4.8L &
5.3L head gaskets are NOT compatible with these cylinder heads.
❑ Stock type intake manifold o-ring seals; GM #12533587 for LS1/LS6
intake manifolds, GM #17113557 for later CK truck intakes, or GM
#89017585 for LS2 intake manifolds.
❑ Exhaust gaskets; Edelbrock #6962
❑ New cylinder head bolts or studs, with hardened steel washers
❑ Heads are machined to accept stock rocker arms, aftermarket
rocker arm assemblies for Gen III and Gen IV engines may also be
used
❑ Correct length pushrods (The required pushrod length is dependent
upon camshaft base-circle diameter and the amount that has been
surfaced from the heads or machined from your block. You will need
to check for correct pushrod length.)
❑ 14mm x 17.5mm (.708”) reach, tapered seat, resistor-type spark
plugs
CHECKING PISTON-TO-VALVE, VALVE-TO-BORE AND PISTON-TO-
HEAD CLEARANCES: Prior to installation, it is highly recommended that
valve-to-piston clearances are checked and corrected to minimum
specs, if necessary. These cylinder heads have larger-than-stock valve
sizes and although they are designed to accept factory pistons in most
cases, it’s possible the use of aftermarket pistons and/or custom
machining of your pistons may be required.
Actual valve-to-piston
clearance should be specified by your camshaft manufacturer. Valve-to-
bore clearance should also be checked, and the top of the bore notched
for clearance, if necessary.
ACCESSORIES: Although Edelbrock Cylinder Heads will accept most
OEM components (valve covers, intake manifold, etc.), we highly
recommend that premium quality hardware be used with your new
heads.
HEAD BOLTS OR STUDS: High quality head studs or head bolts with
hardened washers must be used to prevent galling of the aluminum bolt
bosses. Edelbrock head bolt kits #8596 (pre-2003) and #8595 (post-
2003) include all head bolts needed for use with these cylinder heads.
New production head bolts may also be used. New style blocks use GM
head bolt kit #11519772. Old style blocks use GM #12498545
(See
Note under Figure 1 for year span of old & new style blocks).
Because factory bolts are a torque-to-yield type fastener, the stock head
bolts CANNOT be re-used. The tightening procedure listed below Figure
1 is for OEM torque to yield bolts only. Edelbrock bolt kit #8596 should
use the torque values listed in the Installation subsection.