Here it is, just like we promised. This second installment of Mike's LS swap picks up right where we left off last month with the location and mounting of the fuse panel and fuel pump relay and onward through the balance of this informative engine swap.
The harness has a fuse panel and fuel pump relay that need to be mounted. The fuel pump relay will go in the passenger side kick panel area and the fuse panel will go on the 1x1 square tubes within reach if needed. The harness also includes a connector for the diagnostic connector; it will go in the glovebox. This is where you hook up a code reader to find trouble codes that have been set if there is a problem. A check-engine light lead is also provided and I will install one over by the computers.
Switching to a fuel-injected engine will require an upgrade of the fuel system. The fuel pump needs to be electric and mounted in the tank for best results and longevity. The frame-mounted fuel pumps just don't seem to last with the rigors of daily driving.
Most EFI systems use a feed and return line. The feed line comes from the pump, through a filter, and goes to the inlet on the fuel rail. The return comes from the fuel-pressure regulator of the rails and goes back to the tank. Around 1998-99, they switched to a single feed line. GM has the return line at the filter now and Ford uses a check valve in the pump itself with no return line. Mark sent along a fuel filter kit with a Corvette filter and the required fittings with -6 connections.
I like doing all the needed fuel lines in 3⁄8-inch or -6 if using stainless. I use -6 stainless flex hose to connect the tank to the steel lines, and the feed line to the fuel rail.
Choice of fuel tank is up to you and stock ones can even be modified with an electric pump setup by someone familiar with what's required. There are many fuel tank fabricators out there that make some really nice tanks these days, covering many applications. We're using a new stainless tank with the pump installed and the ports provided for the feed and return. This beauty comes from Rick's Hot Rod Shop. He builds awesome stainless tanks for Ford, GM, and Chrysler muscle cars and hot rods. Ricks tanks are carried by Jegs, Summit, Classic Industries, and Year One to name a few. Tanks can be ordered direct and custom tanks are also available.
With the tank mounted, I can figure where I want the hardline to start from and run to. From that point I bend up some welding wire to the shape and fit I want from the steel line. It will run to where the fuel filter is mounted. I bend up the hardline and install it with the clamps to hold it to the framerail. Then I bend up more wire running the steel line up to the engine area. Next is the return line, figured the same way with the welding wire. You certainly could hook the hardline right to the tank; I find that a flexible connection makes removing the tank in the future an easier process in most cases.
The fittings on the fuel filter and the feed line to the rails have -6 fittings, so even though I'm running regular steel line, I'll still use the -6 AN nuts and sleeves on the lines. I just give the steel lines the same single style flare the AN's use. The fuel tank has 3⁄8-inch pipe ports so I'll get a couple of 3⁄8x-6 fittings for that, the three steel lines used will need -6 nuts and sleeves, three unions to connect the flex lines, and the flex line fittings, two -6 straight and two -6 90's. The 90's will go to the tank.
The hard line I use is 3⁄8x60-inch steel fuel line from the parts store. These two lines made it up the frame and were joined with two shorter pieces to get to the filter that was mounted up just behind the battery on the inside of the framerail. You want to find a spot that is easily accessed so you can replace it when needed.
The back of the filter has the two lines, the front toward the engine has one. Of the two, the bottom one is the feed and the middle one is the return. The hardlines are bent up and connected to the filter keeping with this relation.
Street and Performance has a flex feed line that connects the stock fuel rails and runs down behind the engine and down to the passenger framerail. Where it ends determines where the hardline will end. I make up the short piece of hardline from the filter to a -6 bulkhead fitting and clamp the line in place, and then connect the feed line.
The flex lines at the tank are made up and fit and since this panel truck has a raised floor, I'm not limited in how the lines can run. The fuel sender has been swapped over to the new tank; it and the pump have been wired, so the fuel system is done.
We ran into a problem with the headers on this installation because of the aftermarket crossmember's design. Those that are running a Mustang II or Flat Out Engineering's Corvette crossmember shouldn't have much of a problem finding headers. The only point of interference is the steering shaft and driver side header. Some repositioning of the bottom of the steering column will help. Don't be afraid to move the bottom of the column out, away from the engine somewhat to give the steering shaft a bit more length, and in turn, clearance at the header. Another trick is using three steering U-joints and a support bearing for the shaft and you can snake the shaft around anything.
This exhaust system was done by Street Rod Mufflers in Corona. Since headers had to be made, the best set by far are long tubes. The set we got is just beautiful. They made and ran the whole system all the way back, then had it all Jet Hot coated. This was money well spent. A great set of tubes that will give us 15-plus horsepower over stock manifolds and the complete system coated and installed. By getting the exhaust system done and out of the way now, as I wire the engine I will know where to steer clear of the exhaust when routing the sensor wiring to the lower part of the engine and the O2 sensors. Plus when it's all wired, we can fire it up and see how she runs.