I bought my truck when I was 16 with the 4.3 in it. I drove the **** out of it for 2 years and swapped a carbureted 383 sbc in there. Drove the **** out of that for 2 more years. I just built a 408 iron block from a 6.0L LQ4. Dropped that in last summer, and it is by far the best way to go. If you can find a 5.3, go with that. I get 24 mpg with the 408 ls motor in it and put down 435rwhp with stock components. I got 15mpg with the V6 and around 13 with the 383.

My point is, your going to get tired of the v6 real quick. And if your already thinking you want to make it fast, don't waste your money on the 4.3.