Which one do you have? The earlier versions are a mite easier to fit, sometimes. You'll need to fab up tank mounts, the Savage frame makes a mockery of 95% of the tanks ever built, from any manufacturer. Mine is an old dirt track or ATC tank that somebody had hammered the base in on to fit a different twin spar frame. It fits, but I had to leave the top most upper motor mount bolt out...

I tried dozens of tanks on mine when I worked at a bike shop with attached junkyard. Most Sporty tanks are too long.