Oh What Choices: 5.3L or 6.0L ???

[nsulacountry]

Long time lurker, first time poster.

I have a 1979 C20 Bonanza that is my candidate for a LSX transplant. I have seen some awesome 4.8L and 5.3L builds, some turbos! I have not seen as many, but have seen members drop in a 6.0L as well. With time and money, any of these can be wild rides!

Here is my situation. Bone stock truck. Will be towing with it, mostly farm duty. Tractors, hay, ect, on fairly flat terrain. Occasional trailer weight to 14k (gooseneck). 55 mph is all I need for towing. I am currently doing this with a 2001 K1500 4x4 with a 5.3L, 4L60E, 3.73, 178k mileage.

The C20 is 2x4, TH400. I'd like to keep the TH400 for simplicity. I know a 5.3L is more powerful than the tired 350 4bbl. Rear axle is 3.73, 10.5" corporate. It tachs 3000 rpm at 65 currently. 4.10's and a locker may be in the plan as well.

I'd only put around 2000-3000 miles a year on this build. Farm and play. I don't want to get involved with cam swaps, turbos, and the like. A good tune, dyno tune will be done once up and going. Intake and or injector upgrade would be entertained. I will need AC compressor functional. Stock or high mount?

Do you, the reader think the LM7 5.3L (285 hp, 335 ft/lb) would suffice, or should I go LQ4 6.0L (300 hp, 360 ft/lb)? Is the LQ9 6.0L (345 hp, 380 ft/lb) worth the price premium? How much can be gained with an awesome tune? How many miles on a pull out would be too much for a drop and play conversion? I have seen less than 100k to 300k available. I know a neighbor put +450k on a LQ4 before it lost oil pressure.

Looking forward for some advice. I'm excited to take this on!

CT