At the end of last issue's story, I was hoping we'd be able to wrap up the LS install this month. As seems to be the running theme here currently, it didn't quite turn out that way. So rather than glossing over a lot of the little things, it's much easier to just take the time and address everything appropriately.
There are three goals I'm trying to accomplish with this install. First is to do it as low-buck as reasonably possible while using good parts, so that someone could do this in their home garage. Remember, the engine is a surprisingly affordable wrecking-yard piece with stock internals. The second thing ties in with the first somewhat, but to do the install without relocating the gas tank. Why, you ask? Cost is one factor, but also so this can be done on a finished truck (with nice paint) where relocation isn't a factor, especially with the filler neck. This saves more time and money. The third part is to have a fun, powerful, reliable, AND economical truck to drive.
This month we're covering the fuel system and TV cable adaptation to use a 700-R4 transmission behind the 5.3L LS engine. The stock gas tank just happens to be a "new" stock-style unit from Brothers Truck Parts. Before you feel you've been bamboozled into buying a new tank, let me explain. Welding and gas tanks don't go well together. The new tank is affordable compared to many of the under bed tanks, most of which are usually aluminum, not to mention aren't set up to weld on. A bung for the return line for the fuel injection needs to be welded into the tank and we don't want to be responsible for any explosions! Plus, my old tank needed replacing regardless.
Here is the brunt of the parts...
Here is the brunt of the parts we'll be dealing with this month: The new stock replacement gas tank from Brothers, the pre- and post-fuel filters and external fuel pump from Turn Key Engine Supply, ProClassic AN fittings and hose from Russell.
The external fuel pump and filters from Turn Key Engine Supply can easily be mounted on the inside framerail with rubber-lined Adel clamps (available at hardware stores). In fact, there was all but one of the mounting holes I used already in the frame from the factory, making things even easier. Plumbing the fuel system requires 3/8-inch lines, which in AN sizes is -6. A few sticks of 3/8-inch hard line and -6 AN fittings and hose from Russell took care of the rest. Russell's cloth-braided ProClassic hose is a breeze to use compared to braided stainless variety. Because there are so many variables from truck to truck, lay out all the fuel system parts and map out the fittings you'll need and then go order accordingly.
In this day and age, there seems to be no reason not to use an overdrive automatic transmission like a 700-R4 if you do any amount of driving. While many people have used the later 4L60E and 4L80E trannys with LS installs, I felt I was already taking a big enough plunge with the engine swap and had a perfectly good Gear Star 700-R4 in the truck. Luckily, Bowtie Overdrives makes a kit to mate the TV cable to the LS engines. Without it we'd be dead in the water. If you've messed with TV cables before, you know they must be set up right or else!
Well, that about does it for this month. Follow along with the photos to get a better idea of what's going on. As I type this, I hope to be driving the truck within a week's time, so next month's installment should (hopefully!) be the conclusion. We'll be wiring and firing this baby in no time!
Here's a better shot of the...
Here's a better shot of the smaller pieces. The pre-filter fuel pump, and post filter are laid out how they need to be installed. I put a male -6 AN to 7/8-14 thread adapter into the inlet of the pre filter instead of using the fitting for 5/8-inch hose that it came with. There will be a 5/8-inch hose connection between the pre filter and the pump, everything else will be -6 AN.
Some of you might be wondering...
Some of you might be wondering why I'm replacing the stock tank with a "new" stock tank. We'll get to that, but the old one needs to come out first. Save all the mounting bolts, brackets, and clips as they will be reused. I already stripped the frame of the stock fuel lines since we're making new pressure and return lines.
Here's one of two reasons...
Here's one of two reasons for using a new stock tank--we have to drill a hole and weld a bung into it for the return line. I'm not about to tell you to weld on your stock tank because that's an obvious safety issue. You might be able to have a radiator shop do it for you, but a new one from Brothers is fairly inexpensive. Use a vacuum with a 3/4-inch drill bit to help eliminate chips in the tank.
I got a steel 1/4-inch NPT...
I got a steel 1/4-inch NPT (pipe thread) union from the hardware store to use as the bung and welded it in. Worked like a charm and there was no threat of the gas tank exploding from existing fumes since it was new. The Russell 1/4 NPT elbow to male -6 AN threads into the bung and then a -6 tube nut and sleeve will screw onto the elbow once the hard line is made.
Now the new tank can go back...
Now the new tank can go back into the truck. I also got a new filler neck grommet from Brothers since mine had hardened over the last 30-plus years. Remove and reinstall your old sending unit if it is in good enough shape; if not, put that on the list from Brothers.
Go get a few long sticks of...
Go get a few long sticks of 3/8-inch (for -6) hard line from the auto parts store and borrow or buy a nice 37-degree single flaring tool like this one from Ridgid. AN fittings don't use double 45-degree flares like inverted flare fittings. A quality tool like this will make the job much easier.