it will spin the same # of rev's so your good there. I think (don't quote me though) it takes a 71" belt, but it's easy enough to figure out, just hold the tensioner in the middle of it's range & put a string around every thing in the propper routing, & measure the string ,thats the length of belt you need. you'll also need a ribbed tensioner pulley (just get a pulley from the same year v-6 as your GT & you'll be all set) to swap over.
MM BRACKET RACING CREW CO-FOUNDER
2012 300a GT A6......10.78 @ 124.........sold
2014 301a GT A6.............12.73 @ 112........d/r only