...Think this would get me the torque I want? I'll be running 3.50 gears to start and maybe switching to 3.33's
The Y will definitely do it. They were used in much more heavy duty applications than a 19 foot trailer. The question is will it do it at the speed you want to travel. That answer is most likely. I haven't built one for towing, yet, so I can't help you out much there.
I don't think your choice for rear gears is the best. The only reason to go lower is fuel economy, but if your truck can't handle the load as a result, it defeats the purpose. If towing AND fuel economy are a concern, consider a short rear gear and an overdrive transmission. The tires are tall enough on these that you can get decent mileage with overdrive. I got back from The Y-Block Shootout last night, in Columbus Ohio. I haven't calculated everything yet, but I went about 200 miles between fill ups and used about 11.5 gallons each time, so that's about 17.5mpg at 65mph (a new personal best!). This is with a 3.70 rear and 28" tall tires. I'm planning to try a 4.11 when I find one because I have a hunch that it will increase my mileage because at 65, it's about at the ragged edge of the beginning of the power band. I don't hear any knocking or anything, but it is really sluggish at 65mph.
A few things to do
Zero the deck and use composition head gaskets (as opposed to steel shim). A 292 with even the highest compression heads will not have much more than 8.5:1 with flat top pistons. 0 deck increases compression, to get you close to the maximum with flat tops and the heads you choose. It also increases your detonation resistance and you should still be able to run regular gas. It's also a pretty cheap procedure while the engine is torn down and at the machine shop, anyway. Compression helps you out everywhere, particularly since it is so low to begin with so do what you can to get it up.
You can use steel shim gaskets if you really want, but leave the pistons about .030 in the hole, instead of 0 deck because shim gaskets are thinner.
You have already mentioned dual exhaust. Any dual exhaust is better than the crossover single exhaust. Headers will get you a little more than the rams horns, and possibly be cheaper.
Good ignition. A pretty reliable setup is to convert your distributor for Duraspark internals and to use that in conjunction with an external box. The Duraspark distributor components are very reliable and fairly easy to find in the middle of nowhere. I've heard that the Duraspark boxes are not as reliable but have no experience with that. Reliable or not, it is easier to find, but I'd get something aftermarket for a better spark. If so inclined, you can set up your wiring so that you can plug in a Duraspark box to get you home should your aftermarket box fail because the aftermarket part may be harder to come by.
I have the Duraspark Dyna-Module and Inferno 2 coil, from Performance distributors and it has been reliable so far. I have 2 trips to Columbus, about 1400 miles each, and lots of local driving in Atlanta heat on them and mine gets driven. It doesn't just come out on good days or just for shows.
Charlie, good info. Thanks. I went to the link provided in the crate engine thread. The place is called S&J engines and they're in Spokane, Wa. That's about 20 miles from my house. They'll have an engine with a cam upgrade ($75) for &2009 and change ready tomorrow. 7yr/100K warranty.
Find out how much extra to deck the block. You might find more than a point of compression right there and you will be glad you did it. Now is the time to get that done. If you don't do that, you could have no more than 7.5:1, assuming you got the highest compression heads.
Something I forgot to mention is if the block and/or heads are milled, you can run into intake manifold fitment problems, in which case, the intake, or intake flange on the heads have to be milled. Since you are so close, maybe you can take the intake so they can check that for you. It will add to the cost but it is worth it in the long run. More power, more torque, better fuel economy, more detonation resistance.
Well the money just isn't there to have the block decked or the heads shaved. The cam upgrade is what he calls a 265 grind. My internet research indicates a carb and exhaust upgrade is recommended with these, regardless of manufacturer. I will be going with the ram horns and dual exh. I'm thinking my 1.23 venturi Autolite 2100 may work well with this cam. Should I try that or go with the Holley 350 2v? 4v carb is out of the question.
T98 is the trans I'll be using to start.