While it is possible to change the yarn weight/gauge for any pattern you are knitting, it is important to consider that doing so is not simply a matter of plugging in numbers to a gauge calculator and knitting to a new gauge. While gauge calculators are a great tool for knowledgeable knitters who understand the mathematics behind them AND all the other factors involved in garment construction (fabric type, drape, fit, etc.) they are not recommended for newer or inexperienced knitters.
When you modify the yarn type from what was originally intended in a pattern, you have to consider stitch and row gauge, appropriateness of the fabric, sizing, depth of yoke, stitch pattern, and many other factors. Merely adjusting the gauge without other necessary changes to the pattern can result in an ill-fitting sweater.