I'll be in the market for a new truck soon.
Are any of the new GM V8's based on their venerable 5.7L (350)?

It's what I've had on my 10yr old GMC K1500.
I love that motor!

Jeff  

Hey Jeff,

You've got a couple good choices, depending on what you'll be using your truck for. In the 1500 configuration, GM has a 4.8-liter V-8 with 295 hp and 305 lb-ft of torque. The 5.3L V-8 has 315 hp and 338 lb-ft of torque. And the VortecMax 6.0L V-8 has 367 hp and 375 lb-ft of torque. And stunningly enough, they all have right around the same fuel economy numbers because the two bigger V-8 have AFM (active fuel management, which include the cylinder deactivation modes). The 4.8L is EPA rated at 15/19 (city/hwy) in 4WD. The 5.3L is rated at 16/20 in 4WD. And all 6.0L trucks are rated at 15/19 mpg. Check our long-term updates on our Chevy Silverado (last year's Motor Trend Truck of the Year Winner) on both the Truck Trend and Motor Trend websites to see how our truck has weathered some big city abuse and long-mile driving. Hope that helps.  

Thanks.
But I was looking more for info related to bore & stroke & geometry of the V-block casting. Are any of the 5.3L or 6.0L variations similar in engineering to the 5.7L on my 98 GMC?

FYI - I need 4WD and I'll be towing a camper (5,000lb - 7500lb range).

Thanks,

Jeff  

GM tells us bore and strokes are all over the map depending on various sizes for the new engines; however, the V angles and bore centers are identical to both Gen II (yours) and Gen III (from previous Tahoe/Yukon and Silverado/Sierra). The engineers worked very hard to keep the compact size, low mass, component interchangability and simplicity of the new engine similar to the original 350 design. The result overall meant more torque and better fuel economy. We've done two trips with our long-term Silverado crew cab with a 6,000 pound trailer and we were happy to have the 6.0-liter when passing at altitude. In fact, we're having the optional factory towing mirror installed on our vehicle because for some reason they didn't get installed when ordered. If you're going to order a new one, we'd recommend the NHT package to get the extra engine cooling.  

Thanks Mark.

I whole-heartedly agree about the NHT package.

Is the 6.0L an aluminum block motor? If so, is there any long term reliability history on the 6.0L or similar sized aluminum block motors?

Jeff