First I'd try swatching with the heavy worsted and see how far off you stitch gauge is. If it's close you could get by with a change of needles if the fabric is OK. Since the yarn is thinner it may be a little too loose and airy.
If you don't like the fabric, then try another swatch with the worsted doubled. Regular worsted doubled is just about bulky weight, but I'm not sure how the heavy worsted will be. Doubling may be your best bet.
Good luck and Happy Knitting :XX: :XX: