94 Caprice Wagon

Hey Gang:


So I'm looking to hop on that 'LS-based' bandwagon lol. After much deliberation, I am more or less convinced that an LQ9 6.0 will be most suitable motor for my application. I am a bit apprehensive about a few things though. The car in question is my forum namesake, a 94 Caprice Wagon, it has been set up(fairly well) as a relatively capable and miserly tow pig by its previous owner. Right now it has the original 5.7L LT1 tuned for 93 octane gas backed by an NV4500 and a 9.5" 14BSF with 4.10s. I am running LT215 85 R16 Low rolling resistance tires(about 30.5" tall). Its a solid car with a very clean chassis and is much more capable than many 1/2tons I have driven in regards to towing. As it stands, it still manages to get very high 20s on the highway at 70mph. The mileage easily gets into the 30s if I drive a bit like a grandpa lol. The LT1 is a solid runner too. I have been told that it has "the most robust opti-spark that you can get." I just want something a bit more modern with more support. I have a few modifications in mind for the car, but I would rather implement them after the swap(If I actually do swap it) The A/C and Power steering were deleted by the previous owner for instance. I did retrofit it with power steering(swapped the manual S10 steering box for an Impala SS one and powered it with a Volvo electric PS pump). I did this to easily facilitate an engine swap down the line. I would like add A/C again too, at some point.

So anyway I wanna go 'LS-based', but I have no desire to go fast(this thing is too heavy and shifts too slowly for that anyway lol). I would like to maintain similar fuel mileage and relatively low end torque. I have seen lots of threads comparing 5.3L and 6.0L equipped 800 series trucks. A lot of the differences in performance(in regards to towing and fuel mileage) seem to boil down to the chassis that the motor is installed in. I am kind of looking for info on how they compare(again towing and/or fuel mileage) when all other factors(ie:chassis) are more or less the same. I was also curious about what kind of mileage people have gotten out of these motors when installed in a car instead of a truck. My Caprice with some tools and 1/2 tank of gas is about 4950lbs(maybe a bit less I think my gf was in the car too lol it was 5100 with both of us in it); but it is much more aerodynamic than a Suburban or Tahoe and is riding on low rolling resistance truck tires. The 6.0 seems to get a bad rap as a gas sucker, but part of me thinks that has more to do with the driver and how it is set up in the vehicle it is installed in. I am curious what kind of mileage people have gotten with he 6.0/T56/4l60/80E in various cars as well. That seems to have been done quite a lot.

For my application, the 5.3 seems like it would be a lateral move at best compared to the LT1. The 6.0 does get a lot of praise in the gasser towing department. I already have a stout driveline to go behind it. My thinking is that I will get my hands on a cheap, Rust Belt Special: Escalade, Denali, or Avalanche. I'll beat on it, put it through its paces, use it as a benchmark of sorts, and then part it out once the truck around it starts to give up. Thoughts? I am a long time lurker, this thought has been on my mind for a while, and this seemed like one of the better places for me to ask. I brought the 5.3 into the equation just because it is a bit easier to find and seems to get pressed into tow pig duty often as well. Does the 6.0 have a more suitable torque curve than the 5.3? The 5.3s curve honestly seems slightly less ideal than the LT1 on paper. I have driven some 5.3 trucks that got great mileage and seemed like 'decent' tow vehicles with a 4L60 and highway gears. All that said, I live in the Midwest and don't tow super heavy on a regular basis.(I do tow in the 3-5k range regularly in the summer). I don't drive this car in the winter unless I take it south. How would you build or modify a 6.0 for my application? I'm not particularly worried about mileage, but for the work, I would like to have a similar, if not more suitable torque curve and somewhat 'reasonable' fuel economy. I have a mid-sized truck that I tow with too, so it isn't my only TV, I just like having it as a capable and more comfortable alternative.

I should add that the transmission has been modified with a .643 overdrive. (There is a big gap between 4th and 5th) With 30.5" tires and 4.10 gears, the motor turns just over 2k at 70mph.