The Eastern Conference Finals do not begin until May 20, so tonight’s Knicks-Heat clash will have to do as a potential preview. The raging-hot Knicks have won eight straight games, their longest streak of the Carmelo Anthony Era. They carry that streak into AmericanAirlines Arena tonight for the last South Beach showdown of the season against the Heat before the conference rivals potentially engage deep in the playoffs. There’s no historic Heat winning streak on the line — their 27-game surge was interrupted last week — but there’s plenty of intrigue, anticipation and a chance for the Knicks (46-26) to win the season series, 3-1. “We can’t keep putting that pressure on us, saying this game or that game is a measuring stick,’’ Anthony said. “For us, we’re doing what we’re doing, playing extremely good basketball and they’re coming off a hell of a streak. We’re going out there trying to win a basketball game. It’s not about measuring ourselves against them.’’ It would be hard to fathom Heat president Pat Riley resting LeBron James and Dwyane Wade in front of the home fans as the Heat did Sunday in San Antonio as a bit of payback for a November incident, when the Spurs did not use their best players in Miami. But the Heat yesterday listed James (strained right hamstring) and Wade (sprained ankle) as day-to-day. Starting point guard Mario Chalmers also sat out the Spurs game with a sprained ankle. If the three Heat starters do not play, it may be because Riley realizes the Knicks stand to gain more from a legitimate victory and it may be best to save the varsity for May. “You definitely want to see them at full strength, so there’s not a built-in excuse,” Steve Novak said. “If guys play, it’s cool,’’ Anthony said. “If they don’t, it’s cool.”