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LT1's Fuel System Modification - Project Snowball, Part III

Modifying the LT1's fuel system for third gen use

John Ulaszek Sep 1, 2004

Step By Step

Starting at the driver-side frame rail is the easiest route to fueling your LT1. TPI and TBI small blocks will have a 14 and a 16mm metric fitting on the end of the steel lines.

Pure Choice Motorsports offers the quickest way to connect the factory steel lines to your LT1 with a complete kit including everything you will need from the adapter fittings on the frame rail to push/connect fittings on the fuel rail. The kit includes 14 and 16mm metric O-ring-to -6 AN adapters (part No. 5090), fully assembled Teflon lined braided -6 line, and lastly a pair of Push-Connect-to -6 AN adapters. All of the parts appeared well engineered with obvious attention to detail. Both Pure Choice and Aeromotive stressed changes in fuel additives in 2002. If you don't use the appropriate fuel system components, the new fuels will eat right through the lines. Pure Choice addresses these issues with its Teflon braided line.

For many of us, our first engine upgrades involved saving up for a Holley carb and intake--we sure didn't have money left over for fancy braided steel lines and aluminum fittings, nor did we need them. A couple of hose clamps and some rubber fuel line was all it took to feed that Holley. With the advent of fuel injection, fuel lines and fittings are no longer an afterthought. High pressure AN or O-ring fittings and plastic or Teflon lines have replaced hose clamps and rubber lines that fall apart from high pressure and modern fuel additives.

While the LT1's push-connect fuel line fittings may simplify the assembly process for GM, they can easily confuse the rest of us. For Project Snowball, I chose to cut the fittings off the ends of the fuel rails and weld on AN fittings. Converting directly to AN allows me to use an external adjustable regulator from Aeromotive, which just looks cool. I realize not everyone would want or need to take such drastic measures, so I will also cover a much simpler and quicker approach using adapter fittings from Pure Choice Motorsports. While I had a basic idea of what I needed to set up my fuel lines and fuel system, a call to Pure Choice made routing the fuel system a pleasure.

Before I started this project I spent a good deal of time talking to Brett Clow over at Aeromotive about possible fuel system upgrades. According to Brett, the LT1 has excellent fuel rails, but fuel pressure and flow consistency starts to suffer above 350 horsepower as Chevrolet plumbed the rails in series. While Brett admitted there are cars making more than 350 horsepower in stock configuration, those same engines could make even more power if they were converted to a parallel system such that each rail is supplied with fuel independently. Because I may add more power later, I chose to run my fuel rails in series, but upgrade to AN fittings and an external regulator so I would be ready to run a parallel system later. While bumping up fuel pressure will only give temporary horsepower gains on an LT1, an Aeromotive regulator will allow you to run the optimum pressure for a given injector, connect an Auto Meter fuel pressure gauge, provide consistent pressure and look good doing it. In addition to setting up an external regulator, I'm going to cover Aeromotive's on-rail regulator (part No. 13107).

As my car was originally a TPI car I am going to use the factory fuel pump. In order to supply the LT1 with its required fuel pressure, you TBI and carburetor types will have to upgrade your pumps.

To round out this round of upgrades, a BBK 58mm throttle body came from the Summit Racing catalog and a fuel injection pressure gauge came from Auto Meter.

In part III of Project Snowball I will show you how to integrate an LT1's fuel injection into a third-gen's fuel system.


Auto Meter
Sycamore, IL 60178
Summit Racing
Akron, OH
Lenexa, KS 66214
Pure Choice Motorsports

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