This is odd.

I've been out of the loop for years until getting into that accident it somehow sparked my interest in cars again. Maybe because the sooner I rid myself of this Impala and get back to a performance engine (L67+) the happier I'll be. I've been aware of Chevy putting the 5.3 in its higher priced models, but never knew the new GXP Grand Prix'* are using them.

I was reading up on the 5.3 and it appears to be a strong performer, but how is its reliability? DOD seems safe enough, yet I'm curious if any 5.3 owners here have had issues. Then I noticed Pontiac still uses the Series III SC engine in the GT version, where I would have expected the new 3.9. WTF? The L67, or whatever they call it now, is a reliable powerhouse with an aftermarket the size of Texas. So what I ponder is why buy the 5.3 for ~30k when you can save a few bucks on a GT, mod it for the few thousand your saving, and have a more powerful car? Plus it appears the 5.3 is still using the 4T65E-HD, which is what drove my 98 SSEi.

Please fill me in on your logic and "educated" thoughts on this subject.

I think most people here would follow your line of thinking. At the time being there is a huge aftermarket for the L32, while comparatively little for the 5.3. Go with the tried and true. You already know a supercharged 3800 is a beastly motor, and can easily contend with the horsepower of some modern normally-aspirated V8s. If you're on the market, I say you should go with the L32.

* L32 = the new */Ced 3800, if you were wondering

The guys on ClubGP with GP GXPs with the 5.3 seem to be having trans problems sometimes.

Yea, I've only heard about trans problems. My Mom is leasing an 06 GXP right now, and it has about 15K with no issues. However, the car isn't really ragged on much.

Those truck motors are tanks.

I've got the 5.3 in my 00 truck. Can't say enough about the power and reliability. Seems to be an absolutely great motor. With an SC kit available.

I would assume that it won't take long to see a market of adding SC'* to the DOD models;.

The LS4 is another Gen IV engine in the chevy small block family. It'* very similar to the LS1, LS2, etc... it'* slightly smaller, and there is the DOD.

DOD is reliable, if anythign happens it'll be stuck off, in 8-cyl mode.

Why the LS4 over the L32/L67? It'* a V8 (marketing ++) it'* actually fairly lighter then the L32, it has more top end, and a better exhaust note. It also doesn't need expensive parts inside such as cast pistons and rods, a supercharger, and because of the N/A it'* also less complicated.

L32 is easier to get power out of quickly, but Gen IV SBC have TONS of mods, and have just as much headroom for power IMO.

I like driving the GXP because of the all around power. The low end is wonderful, and it has great power on the freeway (something our cars seriously lack).

There is a lot of TM holding it back though, and for good reason. That motor could easily shred apart the trans with no TM, regardless of the trans improvements. I think the guys on CGP breaking transmissions are typically ones who have been modding their cars.

Sorry Boosty, not the same engine