Description This High Volume HPFP Internals Kit provides an affordable way to upgrade your factory OEM HPFP, increasing volume by 36%.  This kit will work on LF4 OEM HPFPs, and was designed to be fully compatible with OEM cams, Tapout fuel cams, Mace Stage 1 cams and Tapout Stage 2 cams.  When used in conjunction with a Tapout fuel cam, Mace Stage 1 cams, Tapout Stage 2 cams and Tapout LPFP, this OEM HPFP internals kit will flow 64% more volume than stock, fully supporting E0 through E85 fuel. AutoTech is the premier manufacturer of fuel pump upgrades for the DI engines because their kits offer the highest quality, solid engineering and great value.  Each piston and cylinder in every AutoTech HPFP Internals Kit undergoes high-precision grinding processes many times during manufacture, ensuring that the most precise tolerances are maintained through the final step.  This is not the cheapest way to make them, but it is the best way.  Each piston and cylinder are match-ground and serialized to ensure absolute precision and the utmost longevity.  Autotech was the first to incorporate plasma DLC coating on HPFP components to reduce friction losses and increase performance.  Others have tried to follow by adding a coating to their parts.  However, the DLC process alone is not enough, since it is not a cure for substandard precision.  The parts must be engineered specifically for the process to take full advantage.  Tuners trust AutoTech’s HPFP in their conversions and upgrades because it works, and works well. GM recommends that both HPFP lines be replaced any time the HPFP is serviced, so we have these lines available as an option.  Also note that a special fuel pump disassembly tool is required. Fuel cam adds stroke to HPFP, and HPFP internals add bore. When used in conjunction, they provide ~ 65% more high pressure side fuel volume.   What fuel system mods are required to run E85? it depends on how much boost you are targeting and how high of ethanol content you would like to run. Some people claim that you can run E30 on the stock fuel system. However, this is a dangerous and misleading statement. We have repaired and/or replaced many engines for people who trusted that negligent advice. Although the stock fuel system can technically handle E30, you will be required to reduce boost down to the point that you won’t make any more power than you could have on pump gas. With our Stage 1 LPFP, fuel cam and alcohol content sensor you can typically run ~ E47 without issue. This is convenient mix of half pump gas and half pump E85. If you add on the AutoTech HPFP internals, you can run up to straight E85 at reasonable boost levels. With the stock or Turbobay turbos turned all the way up on a Kill Tune, you should be safe somewhere in the E60 to E70 range.