I called my dealership and talked with the man who orders all the vehicles for the dealership. I quizzed him about the RPO code motor (L33)
It's a take off from the Corvette line. Aluminum heads and block @ 310HP. Suppose to be cooler running and better on gas despite the extra HP. He says it will be available in Z71's for sure. They are due out in August.
We also talked about the return to rear drum brakes. According to him, along with ABS there is also a system that senses if you have a load or not. And the drums are suppose to work much better dealing with the proportioning and the front pads will not wear out as fast as they did with the old disc and drum system. Hmmmm??
He also invited me in to order one now. I may just do it to get away from the rattler noisy motor in my 03. This piston slap issue that sounds like loose rocker arms is supposed to be resolved.
I'm going in to crunch the numbers this week.

 

I very much doubt that they fixed the piston slap. The issue was supposed to be resolved with the 03 models. Unless they go with longer skirt pistons/different ring packs - it aint gonna happen.

 

It did not happend in 03, in 04 and I doubt it will happen in 05. I thik the worse slapers were the 99 and 00.

 

GM announced that the new series of motors (I guess it is based off the new LS2 block with DoD hardware inside) is supposed to use floating pins and this supposably cures the "slap" so many have complained about. Take it for what it is worth. Time will tell if that one is true or not.

Todd

 

My piston slap is so bad its not even funny. I wish they would have fixed it.

 

from what i read i wouldn't bother ordering from a guy like that. if he thinks in any way the 5.3 is from the corvette line, then he'd better go take a look under the hood of one and after that go look at an ssr or ext trailblazer. the all aluminum 5.3 has been out for a bit, but sure isn't from the vette line. typical salesman.

 

Is that the SSR motor?

 

the L33 will be a new version for 05' of the 5.3 aluminum block and head version from the s/t series. the current version is the LM4.

 

my motor slaps like a deisel..

so i just spray nitrous and give it a reason to slap/knock

 

The aluminum 5.3 block (LM4) started in the Envoy/TB/Ascender clones. I believe it was last year, but not sure.

The LM4 is rated at 290 HP @ 5200 / 330 lb-ft @ 4000. I haven't heard anything about the L33 yet, but I would think it's based on this motor. But really, all of our GEN III motors are "based on" the 1997 Corvette motor.