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How to make the LS5/LS6/L19 454 faster than the 454SS

In 1991, Chevrolet released the Chevrolet C1500 454SS, producing 255hp and 405 lb-ft of torque. However, for the previous five years, from 1985 to 1990, Chevrolet had been producing C/K trucks with the exact same L19 454 engine, albeit with less horsepower, and some models came with the LS5 or LS6 454 engine. The 1987 to 1990 L19 engines produced 230hp and 385lb-ft of torque. The 454SS had a better intake manifold, two 2.5" catalytic converters, among other modifications.


Although with just a few modifications, you can get your 1985-1990 L19/LS5/LS6 454 to produce more power than the 454SS.


MATCHING THE 454SS


THE L19 (TBI)

  1. Remove the Y-Pipe, install long tube headers, and install true duals all the way down (or side-exit if you do that)

  2. Bump up the fuel pressure a couple of pounds, and use the pressure regulator (12-13psi)

  3. PROM tune, they can be found online; they plug into the back of your ECM. You just find a mild one that doesn't require engine or fueling upgrades (unless you plan on making those) and remove your current PROM, then install the new one.

  4. Ensure the fuel injectors are healthy and the intake is clean.


LS5/LS6 (CARB)

  1. Rebuild or replace the carburetor.(Quadrajets are notoriously difficult to rebuild, but are a huge payoff if you get them working properly)

  2. Upgrade intake manifold. (Edelbrock Performer Series is a good example)

  3. Long tube headers and straight-pipe exhaust, around 2.25" pipe.

  4. Advance timing ~12 degrees initially for roughly 30 degrees at 3,000RPM



BEATING THE 454SS


BOTH ENGINES

RV/Towing Camshaft Upgrade - Just look up your engine and "RV towing cam upgrade". These camshaft upgrades typically require few supporting mods; most of these camshafts just need the lifters and springs upgraded. Comp Cams is a good brand; it's where I get all mine.


Heads Upgrade - Either find some used 049/781 casting oval heads or buy aftermarket aluminum oval heads.


All of these mods can typically get the 454 over 300hp and, if tuned properly, up to 380hp.

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