[mikeman]

Originally Posted by Pdwight

2005 Chevrolet 5 3 L33 Vortec Engine with Computer and Wiring LS1 LS2 LSX | eBay

Less than 350HP

yeh stock...
good little thread over here:

L33 5.3 na performance build recipe - LS1TECH

Here is my aluminum 5.3 build:

18K mile 2007 LS4 (aluminum 5.3 w/799 heads): $1000 for engine transmission/harness/ecm.
LS7 MAF: $60 for sensor and pigtail
LS2 TB, Intake, & Injectors: $375
224/232 DoD camshaft, springs, pushrods: $750
LS7 exhaust manifolds: $150
Reworked stock harness: $50 (for pins and heat shrink)

Never pulled the heads or did any porting, just bolted together and tuned.
So $2385 for the basics, or $1810 after I sold the transmission for $575. Best part is when I break it, I can just get another LS4 engine, swap over the parts and do it again. Resulted in 382whp at 6800 rpm and 335 wtq at 5000

and CarCraft..

Dyno Numbers
Test 1 was the baseline test for the stock 5.3L with a GM Performance Parts single-plane intake manifold, a Holley 750-cfm carburetor, and a set of Hooker 13/4-inch headers complete with a 21/2-inch exhaust system and Flowmaster Super 44 mufflers.

Test 2 was the same engine with the only addition being the Comp Thumper hydraulic roller camshaft.

*snip*

TEST 2
peak HP 433@6800rpm
peak TQ 381@5400-5600rpm

Read more: 325 Chevy Small Block Engine - Bolt On A Cam And Heads And Add 120+HP - Car Craft Magazine