![]() In fact, the stroker equaled the peak torque production of the modified 5.3L (438 lb-ft) at just 3,100 RPM. Remember, this compares to a peak of 438 lb-ft from the modified 5.3L. Torque production for the 383ci exceeded 450 lb-ft from 3,600 RPM to 5,800 RPM. After the break-in procedure, the engine was tuned by Westech's Ernie Mena and eventually produced peak numbers of 480 HP at 5,700 rpm and 491 lb-ft of torque at 4,500 RPM. Though not required for a typical normally aspirated combination, the added insurance was welcome once we installed the supercharger.įor this first test, the 383ci stroker was equipped with the stock truck intake and throttle body, a set of 36-pound injectors and run with the FAST XFI management system. The TEA-ported heads were installed using ARP head studs and Fel Pro head gaskets. The factory oil windage and oil pan worked on this application, though it was necessary to space and/or hammer form the factory windage tray for stroker crank clearance. The 383ci stroker from L&R and Demon Engines received the same Trick Flow Track Max cam run previously in the modified 5.3L. Were this a dedicated normally aspirated engine, we'd opt for a slight increase above 10.0:1, but the 9.5:1 will run well both normally aspirated or with the blower at lower boost levels on pump gas. ![]() ![]() This was done to allow us to install the supercharger after running the stroker combination. We selected a set of 21cc dished pistons from Probe Racing for our 383ci to match the 9.5:1 static compression ratio of the stock 5.3L. L&R Automotive was responsible for machining the 5.3L iron block to accept the Pro Comp 4.0-inch stroker crank, 6.20-inch forged steel rods and forged pistons from Probe Racing. The impressive flow numbers offered by the TEA 5.3L head had no trouble supporting our 383ci. This means the TEA-ported heads should offer substantial power gains throughout the rev range compared to stock 5.3L heads. Despite the slight increase in port volume, the more than commensurate increase in airflow actually produced an increase in port velocity. These changes were made with minimal (as possible) changes in port volume. Treated to Stage 2 porting, the revised TEA 5.3L heads offered an amazing 314 CFM on the intake and 261 CFM on the exhaust. In stock trim, the 5.3L castings offer flow numbers near 245 CFM on the intake and 180 CFM on the exhaust. While the GenX 205 heads were likely every bit as effective, even on this larger 383ci, we selected a set of ported 5.3L castings from Total Engine Airflow. The increase in bore size from 3.78 to 3.902 also gave us the opportunity to try another set of cylinder heads. Instead, the 383ci displacement is achieved by combining the 3.902 bore with a 4.00-inch stroker crank (and 6.2-inch forged steel rods) from Pro Comp Electronics. The cylinder wall in the iron 5.3L block limits boring beyond 3.902, so the 5.3L stroker cannot share the 4.030 x 3.75 dimensions offered by the conventional 383ci small-block Chevy. The 5.3L (roughly 324 cubic inches) combines a 3.78-inch bore with the 3.62-inch stroke shared with most of the LS family (4.8L shares common bore with a shorter stroke). ![]() Chevy truck enthusiasts who grew up on the conventional 23-degree small-block will no doubt recognize the 383ci displacement we had planned for our 5.3L, but the LS combination is a different animal altogether. ![]()
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