h2 feeling a bit sluggish when towing, what are my options to increase torque?

[kalantar]

I have 37's with 4:56 gears on it. The gearing has helped but at times I need that extra push to go up the steep grades. A new engine @ 12k plus is more than I would like to spend now, that is good gas truck money there. I was hoping something around a few thousand dollars.

It seems the turbos aren't a good long term solution as well, what about other engine mods? Headers, bigger pistons, anything?