Jensen Monday Club

6 Pack EFi


US Jensen owner Bruce Bridges has undertaken some spectacular projects on his Interceptor 3. Here is his conversion to a Multipoint 6 Pack E.F.I system.


Here’s the original set-up on my 1974 Jensen Interceptor III :0.030 over bore10.75:1 JE lightweight pistons, mild Crane Hydraulic roller retrofit cam, Edelbrock AL  heads, Performer RPM manifold and BG850 carburettor.  The gear set in the diff is 3.54:1.  The Interceptors best ¼ mile  time was 13.20@107 with a 2.2sec 60ft.  Traction limited, but fun to drive!  The other modifications to the car include a Gear Vendors Overdrive, and TCI  2000rpm stall converter.  Headers are highly modified Delta S&S mid length 1 ¾” tubes.

Digging in (we scheduled 5 days to do the job) We decided to install the fuel system first.  Luckily, The Jensen had ready access to the fuel return/sender via the trunk.  Its just behind that steel panel.

Ryan Vowell came out from Pearl City HI to guru on the install.  Ryan’s company, Performance Injection, sells the Big Stuff 3 injection system and Ryan likes to be involved in the installs if possible!  He hand carried the fuel system components on the plane to San Diego!  The huge Essex Fuel pump, filter and Paxton regulator with lots of -8 AN fittings and line were required to fuel the 440. The huge sizing of the fuel system will allow future Modifications to the motor without upgrading the system!  We used rubber vibration isolators to mount the fuel pump remembering what my old Challenger with its red Holley pump used to sound like.   The pump is very quiet!  We are running a return system, so we added a 3/8” return line into the sender unit and routed new high pressure lines to the engine compartment.  We connected the pump to a 40 amp solid state relay for computer control.  The regulator was added with an electric pressure gage to keep track of things.

Next step was to install the manifold.  Since it’s a dry manifold the swap is no problem.  We had already port matched the manifold to our new valley gasket, so we popped it right on.  The fuel pressure regulator and sender for the gauge can be seen mounted to the back of the rear-most throttle body.  We disabled the mechanical advance with a quick spot weld and cobbled a big hole in the top of a spare distributor cap to help set up the ignition.  Since we are using an MSD crank trigger and Multispark unit, the distributor doesn’t do much anymore.


The crank trigger system  was easy to install…provided you’d already figured out what to do with the extra 3/8” offset on your crank pulley.  We actually thought ahead on this one (thanks Doug!) and made new under-drive pulleys (and matching water pump pulley) with the offset built in.  Makes all of the original pulleys look kind of beat though. 

We’d neglected to really check out the wiring harness up until now.  The Big Stuff 3 harness was complete and nicely loomed.  We were able to modify a few line lengths and move the feed through grommet to make it fit like a glove in our unique application. Nice Packard/Weatherpack sealed connectors! The computer is mounted under the glove compartment shelf. Due to the set-back of the motor, there’s virtually no room behind the dash. The finish on the computer’s box matched the back vinyl in the Jensen and is practically invisible.

We added the water temperature sender to a handy unused radiator tank fitting.  The air temperature sensor went into the back of the manifold where the vacuum brake line normally goes.  We tapped a new fitting into the manifold for the vacuum lines.  The Oxygen sensor was mounted vertically into a bung welded into the right head pipe. The manifold pressure sensor (MAP) was attached to the old choke tower and tubed up to the centre throttle body vacuum port.  The centre TB also gets the throttle position sensor.  We mounted the idle air control motor to the front throttle body. 


Not quite the original look under the hood, more of a road racing look with the  tuneablity and reliability of multi port fuel injection. Now we can make those long summer drives to the Mopar and Jensen meets like any modern vehicle… Well not like “any” vehicle…



We started tuning the system with a non-progressive linkage and a bar actuated (stock) transmission kick down system.  We spent a day or two with that set-up before we ditched it and set-up an adjustable progressive linkage and a Lokar cable kick down kit.  We fabricated a bottom plate to fit the stock  6-pack air cleaner element and ordered a 6-pack lid.  The 6 pack MPI fits much better under the low hood of the Jensen than the Performer RPM manifold. We also noticed that the motor was a little quieter, maybe its because the 6pack manifold sits deeply into the valley pan, reducing the valve train noise!   The initial program the guys at Big Stuff 3 included in the computer worked to get us started, and once we got “bugs” worked out of our installation (full throttle travel issues, IAC motor change from Mopar to GM…) the car is more driveable than with the carburettor, the eye watering idle is gone, it starts up on the first turn, and it seems to be getting better gas mileage. The dyno is the next stop.   We also have this system for sale now!  From 900-2300 CFM, Check out for pricing and production release dates!