If you are just installing the flex pipe, my estimate is 10-15 minutes? Really simple bolt on. I did mine when I put my raceheaders in, and it is just undoing two sets bolts, taking the old out and bolting the new in.
My FS Race Header and flex combo came with all new bolts...may want to give Randy a shout to see what size they are..or if anybody has the race header packagin slip all the sizes of the bolts are on there as well...
Just sent you an email. Apparently the flexpipe I sent you did not have the bolt and gasket kit in the box. Totally my bad for not making sure. Sorry for the mess up. Let me know the next time you need something and I'll make up for it