I bought a 2000 5.3l LM7 to build and put in my truck for $300 with 125,000 miles on it. I tore the motor down already and its in pretty good shape. heres the parts im probably going to put into it.....

-Comp Cams

Beehive Springs .625 Max
(spring kit for $300)

Magnum Pushrods 7.4"

Timing Set 7106

XR265HR-15
1400-6700 Rpms
LBS - 115
Duration - In=265, Ex=271
Lift - In=0.558, Ex=0.563

Hydraulic Roller lifter
850-16

Speed Pro Pistons w/ Moly rings .030 over

F.A.S.T. 92mm Intake & 92mm Throttle Body

K&N Intake

True Dual Straight pipe exhaust
(possibly headers if I can get some cheap)

I might put 10:1 compression pistons in it, should I? or should I just keep the stock 9.5:1 ratio? the only thing is, what octane fuel would I have to run with 10:1? I use 87 right now with stock 9.5:1, would it hurt my motor if I kept using 87 with 10:1 compression?

 

The L33 used flattops to raise it c/r up to 9.9:1.


RPO L33 FOR CHEVROLET SILVERADO AND GMC SIERRA
The Gen III Vortec 5300 is available in a new lighter, higher output variant optional on some 2005 Silverados and Sierras. RPO L33 will be introduced in short bed, extended cab versions of these pickups. The L33 features an aluminum engine block, new cylinder heads and a high-lift cam. Torque will increase, and horsepower is expected to exceed 300 in final production trim.

One of the L33’s distinguishing features is its engine block. As with the 2004 LM4 Vortec 5300, the L33’s foundation is a cast-aluminum block with pressed-in iron cylinder liners, similar to the block used for GM Powertrain’s LS1 and LS6 car V-8s. The L33 block is exceptionally light; as a result, a fully dressed L33 is 100 pounds lighter than cast iron-block Vortec 5300s (RPOs LM7 and L59).

The L33 takes its cylinder heads from the LS6. Originally developed for the Z06 Corvette, these heads improve airflow in and out of the engine. With their pent-roof combustions chambers and new flat top pistons (the pistons in other Gen III Vortec 5300s have a slight sump in the piston deck), the L33’s compression ratio increases from 9.5:1 to 9.9:1. This increase improves the engine’s volumetric efficiency yet still allows it to achieve full power with regular grade gasoline.

Finally, the L33 is equipped with a higher-lift camshaft. Maximum valve lift increases from 11.6 mm on the LM7 and L59 to 12.5 mm. The new cam and compression ratio are the primary sources of the L33’s increased horsepower.

The L33 camshaft and cylinder heads were developed in conjunction with the new Gen IV Vortec 5300 (RPO LH6). The design objective was more horsepower for customers who need it, without requiring a step up to the Vortec 6000 (and an increase in operational costs). RPO L33 expands GM Powertrain’s lineup of Vortec V8s and gives GM’s truck customers even more flexibility and choice.

The L33 Vortec 5300 will be built at Powertrain’s Romulus, Mich., engine plant. With its introduction, Powertrain will cease production of Vortec 5300 RPO LM4. The Buick Rainier, Chevrolet Trailblazer EXT and GMC Envoy XL, previously equipped with the LM4, will now be powered by the Gen IV Vortec 5300 with Displacement on Demand. The 2005 Chevrolet SSR will be powered by the new LS2 truck V-8.


RETURNLESS FUEL INJECTION FOR FLEX-FUEL VORTEC 5300
The flex-fuel Vortec 5300 (RPO L59) is equipped with a new ``returnless’’ fuel injection system. Also know as a demand system, returnless fuel injection eliminates fuel return lines between the engine and the gasoline tank.

Launched in 2002, the L59 was the first flexible-fuel V-8 for full-size sport-utility vehicles. This Vortec 5300, capable of operating on fuel that contains up to 85 percent ethanol alcohol (E85), is standard equipment in Chevrolet Tahoe and Suburban and GMC Yukon and Yukon XL. E85 produces 20 percent less carbon dioxide than gasoline, and in some instances costs less. The L59 adjusts seamlessly between gasoline and E85 operation, giving customers hassle-free choice.

With its flex-fuel capability, the L59 fuel system is unique among Vortec 5300s. Because ethanol has fewer BTUs (less energy) than the same volume of gasoline, more fuel is required to produce the same horsepower at wide-open throttle. The L59 is equipped with unique injectors with a greater cone angle and higher maximum fuel-flow rate. To counter the more corrosive effects of ethanol, its fuel rail is manufactured of a high-nylon composite. Maximum fuel pressure is reduced slightly compared to other Vortec 5300s. Finally, a light-reactive fuel sensor is used to measure fuel composition from 100 percent gasoline to 85 percent ethanol. The sensor determines the gas/ethanol mix and directs the Powertrain Control Module (PCM) to adjust timing and spark advance accordingly.

Nonetheless, the returnless principal is essentially the same for the L59 as it is for other Vortec 5300s. Before model year 2004, the L59 used a return line to manage fuel pressure by bleeding off excess fuel at the fuel rail and returning the excess to the tank. The new system eliminates the return lines and moves the fuel pressure regulator from the fuel rail on the engine to the fuel tank. Because it delivers only the amount of fuel need by the injectors, and returns no fuel to the gas tank, the returnless system essentially eliminates heat transfer from the engine to tank. This reduces the amount of vapor generated in the tank and captured by the vehicle’s Onboard Refueling Vapor Recovery (ORVR) system.

The returnless fuel injection allows the L59 to meet near-zero evaporative emissions standards ahead of federal and California Air Resources Board mandates. All Vortec 5300 variants are now equipped with returnless fuel injection, and certified for sale in all 50 states.


FLOATING PIN PISTONS
The Vortec 5300 is equipped with new floating-pin pistons. First used on GM Powertrain’s Vortec 6000 H.0. V-8, these pistons feature wrist pins that “float” inside the rod bushing and the pin bores in the piston barrel. Previously, the Vortec 5300 used a fixed-pin assembly, in which the connecting rod is fixed to the piston’s wrist pin, and the pin rotates in the pin bore. Snap rings now retain the wrist pin in the piston, while the rod moves laterally on a bushing around the pin.

The Vortec 5300’s pistons, piston rings and connecting rods are identical to those used previously. The new floating-pin assembly allows tighter pin to pin-bore tolerances and reduces noise generated during engine operation. In the Vortec 5300, the floating pins are particularly effective at managing “pin tick’’ during hot starts—a barely audible ticking noise the first 45-60 seconds after starting a hot engine, when the warm oil has drained from the cylinders and the piston and wrist pins have cooled at different rates. Vortec 5300 pistons were already validated for 200,000 miles of operation. The floating pin pistons should extend durability even further and reduce operational noise, even in brief, limited circumstances the customer may not have noticed to begin with.


For max performance premium fuel should be used.

peace
Hog

 

if it was me, id ditch the beehive springs and get a full brian tooley duel spring kit " what im running" there rated to .660 lift than there a nice spring. also what are your plans for the truck? a nice 220 cam would be great for a DD truck

 

You're gonna have to spin that 5.3 far beyond 3k to make power with a 265/271 cam. That cam range looks like it might be for a 6.0 and even then it looks optimistic.

If you're gonna do bore work, why not do a .120 overbore and turn it into a 5.7?

 

Cam is the 212/218. Id recommend going a bit bigger as well

 

I wish someone had told me this when I started my 5.3 block build - get a bare 6.0 block and build from there. ALL of the other parts from your 5.3 engine will cross over, and the aftermarket internal engine parts are the same price either way.

Good luck with the build, post plenty of pics!

 

I'd put the higher compression pistons in it and go ahead and just run 93 octane. The cost per tank is like $7 but way more performance to be had. I like the cam choice, it's a great daily driver cam that offers plenty of gains on a factory cam. I went a little bigger, but I have a little bigger stall and 4.11 gears. The higher compression will help keep the bottom end and the bigger cam will pull good up top.

 

I dont want my gas mileage to be horrible in my truck I just want a bigger cam for performance and higher compression but my mileage not drop sufficiently but have alot more horsepower from stock, with the setup that I said about what yall think my horsepower would be around?

 

i have a 04 ext cab 4x4 lm7 with a tr 220 cam 114 lsa, more or less prc 2.5 heads, with 373 gears, 3200 stall, tbss injectors, and stock fuel pump running on 33" tires im getting 21-22 mpg on a 91 tune and the truck hualed Arsh.....

 

The higher compression helps your mileage as long as it doesn't detonate. The setup needs headers to complement it all. It should make at the wheels, what it made at the flywheel factory, maybe a little more. Mine with a TBSS intake, 90mm throttle body, headers, 218/224 cam, cold air and a tune made 330rwhp with factory compression according to what it mph's. It really needs 10.5:1 or closer to it compression. With 4.11 gears and averaging 85mph, I get between 17 and 18 mpg running between Texarkana and El Paso.