With proper heads, cam and intake, either can be made to approach or exceed 100 hp per liter (480-530 hp) or 1.63 hp per inch. The good news for both 4.8 and 5.3 owners is that they have the ability to extract a significant amount of power from their little V-8s. What should be evident is that the two actually produce similar peak horsepower outputs, but the larger 5.3 will always offer more low-speed grunt. In terms of factory power ratings, there is actually not much difference between the 4.8L and larger 5.3L, especially the garden variety LR4 and LM7. It is thought the rare manual trans 4.8s were also equipped with a 312 crank, but that would definitely be the exception. If, however, your iron-block motor is sporting a 482 crank and 121 rods, then you have a 4.8. If you have crank casting numbers ending in 216 and rods ending in 143, then you have a 5.3. Crankshaft and connecting-rod casting numbers are the real key to distinguishing between the two. The 4.8L flat-top pistons are a common (and inexpensive) upgrade for a 5.3L. version of the 5.3L was also offered with flat-top pistons (and floating pins), but the aluminum block is a dead giveaway. It should be mentioned that the (元3) H.O. Internally there are distinct differences, the most obvious being the use of flat-top pistons in the smaller 4.8L. More than one enthusiast has purchased what he thought was a 5.3L, only to receive the smaller 4.8L in its place. Since the 4.8L and 5.3L share the same block (externally marked 4.8L/5.3L), not to mention the same heads, intake, and other external features, it is difficult to distinguish between the two. Given the bore and stroke of each, a better comparison might be the 327 and larger 350, as the 4.8L and 5.3L share the same bore size of 3.78 inches while the 4.8L makes due with a shorter 3.267-inch stroke (down from the typical LS stroke of 3.622 inches). The question we wanted to answer was: How does the smaller 4.8L compare to the 5.3L in stock and modified trim?ĭisplacement wise, the 4.8L is to the 5.3L what the original 283 was to the 327 small-block (technically 293 versus 325 ci). Rather than just demonstrate what the mods do to the smaller 4.8L, we decided to compare it directly to the more popular 5.3L by performing a back-to-back shootout of sorts. Down on displacement to be sure, the 4.8L still has everything that makes a Gen 3 or Gen 4 (LQ, LM or LR) small-block great, including cross-bolted mains, high-flow aluminum heads and a combination just begging for the right mods. We paid just $250 for ours versus $450 for the 5.3. With 4.8L engines powering countless thousands of trucks on the road, to say nothing of the pricing and availability in wrecking yards, the little 4.8 starts to look attractive. They certainly make more torque, but the downer is they also use more fuel. The reality is that, all things being equal, bigger engines make more power. Enthusiasts pass right by the 4.8Ls in their quest to gobble up all the 5.3L motors in wrecking yards as swap candidates. Worst case scenario? They grab the medium-sized 5.3L. Everyone wants a 7.0L, 6.2L or at least 6.0L LS engine powering their trucks and muscle cars. Let’s face it: The little guys never get the love.
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