Hi Performance Automotive
Gaskets
GM-
Pontiac V8 326, 350, 400, 421,
428 & 455
326ci Head
Gasket
|
Part
#
|
Bore
|
Material
|
Pkg
Qty
|
Purchase
Online
|
|
|
3.750"
|
MLS
/ C.O.T. - .040"
|
1
|
|
350ci
Head Gasket
|
Part
#
|
Bore
|
Material
|
Pkg
Qty
|
Purchase
Online
|
|
|
3.950"
|
MLS
/ C.O.T. - .040"
|
1
|
|
400,
428 & 455ci Head Gasket
|
Part
#
|
Bore
|
Material
|
Pkg
Qty
|
Purchase
Online
|
|
|
4.160"
|
MLS / C.O.T.
- .040"
|
1
|
|
|
|
4.200"
|
MLS / C.O.T.
- .040"
|
1
|
|
|
|
4.300"
|
MLS / C.O.T.
- .040"
|
1
|
|
428 & 455ci Head Gasket
|
Part
#
|
Bore
|
Material
|
Pkg
Qty
|
Purchase
Online
|
|
|
4.380"
|
MLS
/ C.O.T. - .040"
|
1
|
|
|
|
4.410"
|
MLS / C.O.T.
- .040"
|
1
|
|
Material Acronyms: AFM -
Aluminum Foam Coated, AM -
Armor Clad, CFM-20 - Perforated steel core with
elastomer coating, KF -
Aramid Fiber, RC - Rubber Coated, S -
Spring Steel
- Installing a COMETIC MLS (Multi Layer Steel) Head Gasket -
The first thing you must do before installing the gasket, check all
associated hardware thoroughly for nicks, scratches, or damaged threads
as well as checking all threaded holes. If the hardware is inadequate
or damaged, gasket failure may be eminent. Also change all the bolts
and tap all threaded holes with the appropriate thread chase or cleaning
tap. All hardware and mating surfaces should be free from any old
sealers, rust, or carbon.
Check your dowel pins as they register the gasket and head into proper
location. Replace worn or damaged dowels. The gasket mating surfaces
must be smooth 50RA or finer. Additional sealer is not required with
Cometic MLS Head Gaskets. The outer layers of the gasket are coated
with a .001" thick coating of viton (a high temperature flouroelastomer).
Check brass rivet location to ensure the brass river does not interfere
with the sealing surface on both the block and head. If the brass rivet
needs to be removed a pair of side cutters will give the best results.
Remove only the brass rivet.
Once the gasket is in position double check all passages and overall
fitment paying special attention to the bore and chamfer. The gasket
should not fall in the bore or lay on the chamfer area. A gasket lying
on the chamfer or in the bore will most likely cause a hot spot and
lead to pre-ignition, possibly causing severe engine damage or gasket
failure.
- Head Gasket Torque Procedure - If you are using
studs or head bolts, torque hardware to the manufacturers specification.
Fasteners works like a springs and must have proper Torque or Stretch
applied to carry the correct amount of clamp force. Also use the
proper lube or thread sealer for the job. All fasteners must be final
torqued before thread sealant cures to achieve proper torque.
Torque the fasteners in the correct sequence. It is critical to follow
manufacturers torque sequence to apply clamp force evenly. A smooth
continuous motion is important for every torque sequence. Re-torque
is not necessary unless using hardware that has not been heat cycled.
Warranty Disclaimer*
Due to the nature of performance applications, the parts in
this catalog are sold without any express warranty or any implied warranty
of merchantability or fitness for a particular purpose. Cometic Gasket
Inc. shall not, under any circumstances, be liable for any special,
incidental or consequential damages, including, person, party or property,
but not limited to, damage, or loss of property or equipment, loss
of profits or revenue, cost of purchased or replacement goods, or claims
of customers of the purchase, which may arise and/or result from sale,
installation or use of these parts. Installations of these parts could
adversely affect the motor manufacturers warranty coverage.
|
