#1) Buy a forged 347 stroker kit (
www.haneymotorsports.com and
www.mustangsunlimited.com sells them). Bring the car to a shop, and have them install the kit. The engine will need to be bored .030 over and will need to be honed. Guestimated cost is around $1500 for the labor.
#2) Buy a forged 347 block (heneymotorsports sells these for dirt cheap) and then just bring the block to a shop, unless you have the ability to get your motor out your car, and have them just swap over all the parts, or you can buy parts (heads, cam, intake) and partially assemble the block yourself, and have a shop install what you've done.
#3) Buy a forged 347 crate motor. Not much needed other than to bring it to a shop, have them pull the old engine out, drop the new engine in, and rehook all the wires back up.