Put a v-8 in it. For as much as you would spend on making a v-6 powerful, you could put a stock v-8 in it and it would be stronger and much more reliable.
2.8's are just about indestructable IMO. Ive had two, one in a 1984 s-10 blazer and one in a 1987 firebird. The one in the blazer had been ran dry on oil countless times, never killed it and it had very high miles. The one in the firebird was ran out of water over and over again. All the way from a crack in a radiator tank, to no drain plug in the radiator at all 0 water. After two weeks driving it in and out of town, i replaced the plug and it didnt hurt a thing. Hell it was driven like a month wth no cooling fan in it, and it ran great up until the day a full size truck drove across the hood.