How to Order

See something you're interested in and wondering how to order it? Unlike most online stores, we don't have a shopping cart, you can't set up an account, and there is no check out process. If you see something you are interested in, email us at "sales" at "". Typically you'll get a response within a day answering any questions you had and providing information on how to pay (normally paypal).

So why don't we just add a shopping cart to our website? The primary reason is that we want to exchange an email or two with you first BEFORE we accept your money. There are probably a dozen reasons behind this decision, but they all boil down to making sure you get what you want and putting you in contact with a person rather than a webpage. It's worth noting that while we often keep a small stock of the smaller items, porting and turbo headers usually involve a customer specific tweak of some sort. As a result, it's just easier to do it this way.

Bobble Struts

Bobble Strut

A bobble strut is used to keep your engine and transmission from rocking front to back when you hammer on the gas. This solid strut will hold the engine and transmission in place more firmly allowing less rock. The strut comes as shown, constructed out of welded steel with stiff polyurethane bushings. Black and Yellow are standard. Other colors are available for an additional $4.

$35.00 + Shipping

Transmission Installation Pins

Transmission Installation Pins

These little pins may not look like much, but they can save you some big time and more importantly, frustration, on your next clutch job or transmission replacement. Using these pins to guide the transmission onto the engine allows you to line everything up without even being under the car. It certainly beats bench pressing the tranmission and sliding it around to find the hole in the clutch disk. Using these pins takes much of the guess work out of the job. If the disk is misaligned you'll know it right away. (See our technical section for instructions on how to do this.)

$10.00 + Shipping


Head Porting (Mitsubishi 6G72 12v SOHC)

Stage 1

Our Stage 1 Heads represent a great step forward in performance by simply cleaning up and tweaking what the factory left behind. The following things have been done to the stock heads:

  • Removed casting parting line from runners
  • Reshaped and smoothed the bowl
  • Smoothed the short-side radius
  • Polished exhaust ports (reduces future carbon buildup) 
  • Checked for flatness (and milled as needed)
  • New valve guide seals 

$250.00 +
Shop +
Core +


Stage 2

Our Stage 2 Heads include everything that was done in stage 1 and uses epoxy to reshape the intake port and tune port diameter for the desired peak horsepower RPM. There is a choice of a conventional tumble port or a drop port (helps high rpm at the expense of the low and mid-rpm.)

  • Tuned to your setup and desired peak horsepower RPM.
  • Epoxy used to resize and reshape port

$400.00 + Machine
Shop +
Core +


Additional Upgrades (All Stages)

Optional Machine Shop Services

  • Back-cut valves  (machine shop cost)
  • 3-angle valve job  (machine shop cost)
  • Schneider 6610 springs ($105)
  • 3.3L springs/LS1 Retainer and Locks (TBD)

As of April 2009, the machine shop charge was $185 for a 3-angle performance valve job.  This cost is provided as a convenience but should not be taken as a fixed cost.  We don't control the prices at the machine shop.


Head Porting (Mitsubishi 6G72, 6G73, or 6G74 24v SOHC )

Stage 1

Ed has made some fantastic progress on these heads. 

  • Short-side radii are reshaped
  • Bowl is modified.
  • Valves are deshrouded
  • Port runners are cleaned up and tuned for the ideal port velocity

Optional Machine Shop Services

  • 3-angle valve job 

As of April 2009, the machine shop charges were $256 for a 3-angle performance valve job + $150 for head re-assembly.  These numbers are provided as a convenience but should not be taken as fixed costs.  We don't control the prices at the machine shop.

$350.00 + Machine
Shop + Core +


Head Porting (Chrysler 2.2L/2.5L 8v SOHC )

Stage 1

Available!  Details coming soon...

Optional Machine Shop Services

  • 3-angle valve job 


$600.00 including Machine Shop

+ Core


(1 head)

Throttle Body Porting



Chrysler 46-58mm

The throttle body exit is opened up to match the rest of the throttle body. This improves low-rpm throttle response.







$25 +
Core + 

Jeep 60mm

The throttle body exit is opened up to match the rest of the throttle body. This improves low-rpm throttle response.

$45 +
Core +

3.0 Intake Porting

Lower Intake

The stock lower intake could use some work, namely filling in the divit in each runner with epoxy and some additional tweaking. 

Custom tweaking is also available.  Contact us regarding pricing specific to your request.
(For example, if someone has gasket matched their upper plenum and the lower could be gasket matched as well.)

If the intake needs to be cleaned, an additional $25 cleaning fee will apply.

$50 +
Core +



Upper Intake (Plenum)

Porting of the upper intake includes

  • Center divider is removed (top and bottom halves)
  • Ribs on the roof are removed
  • Port entry is reworked
  • Exit to the runners is matched to the runner entry




$150 +
Core +

2.2/2.5 Chrysler Intake Porting

1-Piece Intake

Available!  Details coming soon...


$90 +
Core +


2-Piece Intake

Available!  Details coming soon...



$140 +
Core +

3.0 Exhaust Flanges


Interested in building your own headers? If so, you'll want to check out our mild steel exhaust flanges. These flanges are just the thing for your do-it-yourself header project. The flanges come in your choice of 5/16" or 3/8" thicknesses.

Note: Due to a substantial decline in quality from our supplier and other vendors who have emerged offering prices lower than that of our supplier, we are no longer offering exahust flanges for individual sale.

Not Currently

3.0 Turbo Headers

Rear Mounted

After much time in development, turbo headers are now being produced and sold.  The standard rear mounted turbo header replaces the rear exhaust manifold, connects to the stock crossover, and places the turbo just above the rear valve cover. 

The manifold includes a provision for an external 38mm wastegate.

$560 Uncoated

$685 Coated 

+ Shipping


Crossover Mounted

A crossover mounted turbo requires replacing the rear exhaust manifold with a log style manifold resembling the stock front manifold.  The crossover is then replaced with a strudier piece with a turbo flange mounted to it.  The crossover also includes a provision for an external 38mm wastegate.

Shown at the left are pictures of a pair of matching front and rear log manifolds that were built for the last crossover header along with a couple shots of the crossover. 

The individual pieces of this version are sold separately (Rear Log, Front Log, Crossover).  Specifcy which pieces you want when ordering.


Note:  The crossover is constructed using YOUR core crossover pipe.  The flanges, flex joint, and a portion of the stock pipe are re-used. 


Uncoated Log (front or rear)


About Core Charges

Core charges are requested in order to ensure that Kelly-Mulhern Performance continues to have a supply of available parts for modification and re-distribution. Charges are 100% refundable for cores of the correct type/style received within 45 days of purchase and found to be in acceptable rebuildable condition. Cores received after 45 but prior to 90 days will be eligible for up to 50% of the initial core charge. After 90 days, the core charge is considered forfeit. Damaged cores will be eligible for the charge refund less the required cost to repair said damage. Cores requiring repair costs in excess of the core charge or that are deemed unrepairable will not be accepted.  

If desired (and we prefer this), you may send in your heads, intakes, etc for modifcation in order to avoid core charges.

Acceptable Use and Liability

Kelly-Mulhern Performance parts are not certified, tested, reviewed, analyzed, underwritten, authorized, or otherwise vouched for by any type of regulatory entity. As a result all parts are listed and intended for off-road use only. Although we do our best to ensure the highest quality possible, Kelly-Mulhern Performance will not assume any responsibilty or liability for the use or misuse of its products or any damage or injury resulting directly or indirectly from the use of said products. Upon purchase, the buyer assumes full responsibility for the use of these products and any costs, consequences, or liabilities that follow.