Originally Posted by ferrellrooster

Test Motor #4-Mild 383 Stroker

Block: Stock (Bored to 3.902)
Crank: 4340 forged 4.0-inch stroker-Procomp Electronics
Rods: 4340 6.2-inch, Procomp Electronics
Pistons: 21cc dish forged piston, Probe Industries (3.902 bore)
Cam: COMP XR275HR .566/.568 lift split, 222/224 duration split, 112 LSA
Heads: TEA Stage 1 CNC 5.3L
Intake: Stock
TB: Accufab 78 mm
Headers: QTP 1¾-inch long-tube
Peak Power: 506 hp at 5,700 rpm
Peak Torque: 503 lb-ft at 4,700 rpm
Torque Curve: Exceeded 475 lb-ft of torque from 3,800-5,500 rpm

Though the 5.3L LM7 offers plenty of power in modified form, the torque production is ultimately limited by the displacement. The cure for this limitation is as simple as adding inches, in this case jumping from 324 ci to a full 383 ci. The increased displacement will improve not only peak power, but more importantly, average torque production. Basically the bigger motor can make more power everywhere. The additional displacement allows you to equal the power output of the wild 5.3-liter with a much milder combination. The benefit of going the stroker route is improved fuel mileage (over the wild-cammed 5.3-liter) and monster torque curve. The 5.3L block was bored to accept 3.902 forged pistons from Probe Racing, and then combined with a 4.0-inch stroker crank and 6.2-inch rods from Procomp Electronics. The stroker short-block was topped with the same TEA-ported 5.3L heads used on the mild 5.3-liter. Wanting a daily driver, we chose a mild COMP XR275HR cam. The combination offered plenty of power, peaking at 506 hp at 5,700 rpm and 503 lb-ft of torque at 4,700 rpm. Torque production was up by 100 lb-ft over the stock 5.3-liter at 3,000 rpm and by 90 lb-ft at 3,500 rpm.

Test Motor #5-Wild 383 Stroker

Block: Stock (bored to 3.9020)
Crank: 4340 forged 4.0-inch stroker, Procomp Electronics
Rods: 4340 6.2-inch, Procomp Electronics
Pistons: Flat-top forged piston, Probe Industries (3.902 bore)
Cam: COMP 289LR HR14 .624. lift, 239/242 duration split, 114 LSA
Heads: TEA Stage 2.5 LS6 (1.72 roller rockers)
Intake: LSXRT
TB: FAST 102 mm
Headers: American Racing Headers 17⁄8-inch long-tube
Peak Power: 603 hp at 6,400 rpm
Peak Torque: 544 lb-ft at 5,400 rpm
Torque Curve: Exceeded 525 lb-ft of torque from 4,400-5,900 rpm

Like the wild 5.3-liter, this 383 version pushed the limits of driveability, but boy howdy did it make power. Using a 5.3L block, we bored and stroked the 5.3-liter to achieve a final displacement of 383 ci. Unlike the mild version that featured a static compression of 9.5:1, this 383 was sporting flat-top pistons that pushed the static compression ratio to 11.0:1. The elevated compression ratio was combined with a set of TEA Stage 2.5 LS6 heads, an aggressive COMP 289LR HR14 cam and FAST LSRXT (truck) intake. Wanting to maximize power, we even installed a set of 1.72:1-ratio aluminum roller rockers and swapped out the 1¾-inch headers for larger 1⅞-inch versions from American Racing Headers. The extra breathing paid off, as the 5.3L 383ci stroker produced 603 hp and 544 lb-ft of torque. Torque production exceeded 525 lb-ft from 4,400 rpm to 5,900 rpm, making for one sweet torque curve.

So this is were I came up with the combo's and want to build the Wild and use as a DD. What do you think? I may be asking for trouble as a DD with having to have a stall and all. What do you guys think?
Here is the link to the page:
5.3L Bow Tie Builds Mild To Wild - Chevy LM7 Engines - Truckin Magazine All Pages

Originally Posted by greasemykey

i built a 383 with the 2.5 heads and havent had an issue with them. i did however LOATHE the LSXRT and i want to punch the designer in the nuts. its a 1000 dollar piece of ****.