The general rule of thumb for stock cathedral port intakes is LS1 < Truck (‘07 down) < LS6 < TBSS / ’07 up trucks. The TBSS is the same as the newer truck intakes and was designed with the bigger ports of the LS6 but with longer runners to keep the low to mid-range power levels while also flowing a ton up high. To really take advantage of the LS6 or TBSS intakes you need the better flowing 243/799 heads (or aftermarket) and a good cam shaft. Using either on a stock 4.8 or 5.3 with the lower flowing 706/862 heads would see minimal gains or possibly even a loss in performance. Lots of info about this stuff over at LS1Tech and PerformanceTrucks in case you want to read up more…
With all that being said, if all you’re looking for is additional hood clearance and max power isn’t a concern then an LS1 intake would probably work just fine for you and could be had pretty cheap. If you have more money to spend then an LS6 intake would be better and Dorman now makes a replacement that runs cheaper than what a lot of guys are asking for their used ones.
I know you said that you weren’t keen on the idea of shaving down your stock intake but that’d be the cheapest and easiest way to go since you wouldn’t have to worry about potential injector or throttle body issues. There’s a ton of how-to threads all over the net and if you screw it up you can always buy another one dirt cheap lol. Here’s a thread dedicated to shaved/smoothed truck intakes:
http://ls1tech.com/forums/conversion...k-intakes.html
Here's a couple of pictures I borrowed from that thread for some inspiration:
