Ok, first, I don't have anything with a 2LT-E or plan to anytime in the future. With all the peoples with problems with the 2LT-E out there looking for solutions I was hoping to maybe offer up another solution. But I don't know anything about this engine. Was talking with someone that had his 2LT recently rebuilt and was talking about the 2LT-E's problems. He stated that the 2LT head was steel vs. the 2LT-E's aluminum. Is this true? If so, can you successfully mount this head on the 2LT-E block? and run it? That's it.
p.s. OK, so according to Radd Cruisers both have steel heads?
To answer the other part of your question: no, you cannot interchange a 2L with 2LT-E head. The 2LII-T, 2LT-E and 3L heads all interchange however. And my 2LT-E head is most certainly not aluminum.
I think the long term solution for the 2LT-E is to either accept that you have to be ready to replace the head all the time, or to swap in a better engine. As much as I love my 2LT-E powered truck, that's the nature of the beast.