Loose ends. They make up the majority of our projects, yet rarely does any magazine article do justice to those small, albeit important, components that are necessary to get the job done.
Our Project D150 was no exception. Certainly, rebuilding the engine to produce nearly double the horsepower and torque output of the Slant Six was a reasonable task. In doing so, it was well within the power range of a small-displacement Mopar small-block. Now the goal was to take the combination off the engine stand and get it firmly between the framerails.
Follow us through the minutiae involved with getting our D150 on the road, and see if our challenges assist you in getting your project further down the road to completion. Just click on the sidebars below to get the scoop.
The lifeblood of any engine is gasoline. Functionally the original system would have worked fine, however, we needed a more aesthetically pleasing arrangement that also reduced the chances of vaporlock.
The majority of the work involved reforming the fuel lines from straight stock and efficiently routing them in order to gain both function and form.
To keep the engine bay neat, we rerouted as many lines and wires as possibleincludin
A fuel filter was definitely a must, so we chose K&N's billet fuel filter. We snapped the
After we completed our conventional fuel routing and checked for leaks, our Holley 2-bbl w
Optima Batteries recommended a Deep cycle battery for the long hours we spend listening to
From early on, we only considered Optima Batteries for supplying amperage. The aesthetic favorite not only looks good, but also fulfills the deep cycle needs of our D150, due to our audiophile status.
All the hoses and wires were covered with Techflex wire loom. Techflex is a nylon braided
A host of new wires to power the electric fan, signal the MSD Ignition, and route accessory cables required the use of wire loom covering. We turned to Techflex for the braided wire loom, which would give a finished look underhood.
Spark It Up
Proven ignition performance is easily accomplishable, thanks to MSD Ignition and its straightforward installation instructions, which incorporate factory components and aftermarket systems.
We installed the MSD 6AL ignition on the firewall, only to have to relocate it due to clea
We mounted the coil next to the ignition box in order to simplify the wiring arrangement a
Our factory assembly manual and a test lamp assisted us in locating a 12-volt, keyed power
The nature of our accessory drives required simplification, as we added an aftermarket air conditioning compressor. Additionally, the opportunity to remove the water pumpmounted fan afforded us a way to remove the power-robbing effect of the cooling fan.
We lowered a Flex-A-Lite electric fan (Black Magic M150) in place of the original. The Fle
The wiring is found on the side of the housing, which contains an adjustable themostat to
Although the Slant Six is a venerable and efficient engine, it has a reputation for being a hot runnerand were not talking performance here. In order to alleviate the typical concerns of oil and transmission cooling, we added aftermarket coolers to reduce underhood temperatures.
To help with the cooling needs for the transmission and the engine, we installed Perma-Coo
We mounted the Maxi-Cool TM oil cooler in place of the radiator overflow tank. Notice the
The throttle valve lever on the transmission was replaced. This photo shows the old (A) an
Anyone who has attempted to replace a stock carburetor with an aftermarket unit has dealt with kickdown linkage. Fortunately for Mopar enthusiasts, they have a friend in Randy Bouchillon. Bouchillons Kickdown Cable Kit makes head-scratching completely obsolete.
Because we outfitted the Slant Six with a new Hooker header and Holley carb, the original kickdown rods would no longer work. Bouchillon sent us a TorqueFlite Kickdown Cable Kit that installed so easy, were still amazed. This kit works with most 62-and-later Chrysler rear-wheel-drive vehicles fitted with a TorqueFlite transmission and just about any carburetor, including our Holley 2-bbl.
A cable bracket was bolted onto the transmission using an existing hole. We made a small,
We ran the cable down the driver side of the truck frame and looped it back to the transmi
Bouchillon supplied the bracket that mounts to the intake manifold flange using the rear c
We took the truck to TMEC, a local exhaust shop, to have our new Gibson Cat-Back system and Random Technologys high-flow catalytic converter installed. The experts at TMEC evaluated our exhaust system and the factory layout. The final result was clearly a custom exhaust system that looked good and cleverly evacuated the exhaust sound behind the passenger-side rear wheel.
TMEC first measured and cautiously fit all the pieces together, making many modifications
Considerable work was done to gain a perfect fit from the header flange, around the oil pa
The final touch: The Gibson chrome exhaust tip is welded coming out of the right side, beh
Creature comfort was definitely on order and as such, we opted for a little help from Vintage Air. We ordered a complete R134a systemwith the exception of the evaporator coil, where the original sufficed. Our kit even included all the fittings, barrier hoses, and brackets, as well as a pressure switch and expansion valve. To keep things in the engine compartment uniform and looking good, we ordered the polished compressor and chrome drier.
We opted for the universal A/C bracket to hold the front of the compressor...
...and a small slotted bracket to secure the side of the compressor. This would allow the
The condenser was installed with four brackets, one in each corner. Here, a hole is drille
We had Best's Lakeland Hose Service crimp all the fittings onto the hose ends. This photo
Because we used the original evaporator coil, we cut the fitting off the old hoses and, as
The tanks on our original radiator were shot, and while we had made repairs previously, new leaks were now appearing. Rather than continue to repair the down-flow radiator into service, we turned to Be Cool, which built us a custom cross-flow, four-row radiator. The result was better coolant flow and lower engine-operating temperaturescertainly part of the equation for additional performance from our Slant Six.
If we had made the swap simply for aesthetics, we would be applauded. The Be Cool radiator
To further clean up the look and offer rigid hose construction, we used Inglse's CoolFlex
To be brutally honest, we were a bit reluctant to discover the actual output of our Slant Six at Vincis Hi-Performance in Orlando, Florida. Would we meet our goal of producing V8 performance from the six-banger?
On the chassis dyno, we ended up with 140.1 corrected horsepower at the rear wheels and 194.0 lb-ft of corrected torque. According to Vincis, this equals 175 hp and 243 lb-ft of torque at the flywheela whopping increase of 85 hp and 83 lb-ft of torque as compared to a stock Slant Six.
We also widened the rpm range of power, and now the engine maintains an average of 120.5 hp and 178.1 lb-ft of torque through 5,000 rpm. And yes, it will break the tires loose!