ric wrote:
This is just me talking, but if I was in the market for a new tow vehicle I can't even fathom wasting it on ancient technology. That 5.3 engine is just a 305 from the 70's with a little bit of kit added on to it. The ford ecoboost, toyota's offerings, and really diesel is the only purchase i'd make. You can get mid 2000's dodge diesel trucks for almost nothing and they're amazing.
The new line of Chevy engines is far from ancient technology. As mentioned previously in this thread, the pushrod V8 was revamped in 97 when the LS1 came out in the Corvettes. Do you know what is currently in the 5th Generation Camaros? How about the C6 Corvettes? And yes, even the Silverado, Sierra, Denali, Avalanche, Tahoe, Suburban (you get the point) have the same old school pushrod V8 that is only a variation of the bigger motors in the sports cars.
I know plenty about the whole line up of GM's small block Gen III/IV motors. I have owned four 4th generation Camaros and my current one is rocking a 6.0L from a 2003 Silverado that will be fed by a 76mm turbo. My old 2000 SS put down 390 rwhp with full bolt ons (headers, intake, etc.) and a simple cam/spring swap. The 5.3L is 325 CI and leaves about 10-15 hp on the able compared to the 5.7 346 CI LS1. These motors are so easy to get power out of it isn't funny. I know a lot of people in the LS community (general term for a Gen III/IV motor) that are scooping up 5.3L motors from trucks because they are plentiful, dirt cheap, and can make big power.
So where am I going with this rant you ask? The 5.3L is MORE than enough to tow a 20' boat. I own a 02 Avalanche with the 5.3 and it towed my buddies Crownline 225br with a big block like it was nothing. Pulling my 18' Horizon it barely breaks a sweat. My cousin has a 07 Duramax that he uses for farming but also has a 2011 Tahoe. He pulls his 2011 Crownline 245SS with the Tahoe and it does perfectly fine.
IMO, a diesel is not needed to pull a boat of this size. Would it make it easier? Sure! Diesel repair is expensive though.
I have driven a newer Dodge Hemi and it got TERRIBLE gas mileage and did not feel any more powerful than my Avalanche, although I know on paper it may have more power. Any of GM's Gen III/IV motors are EXTREMELY reliable and cake to work on.
elhippie64, I know you started this thread a month ago, but if you haven't gotten a new tow vehicle yet then there is no reason not to go with the Sierra you have been thinking about. The 5.3L makes more power in all RPM ranges than that 5.7L does in your Tahoe currently, and will get better gas mileage.
Good luck!