A 17x8 with 5.5" of backspace should not hit the UCA's. I was at about 6.2" of backspace before my 18x9's hit the UCA's at full steering lock and suspension extension, and that was just barely a touch. 17's hit the outer tie rod first, but that's usually not an issue until you go past 5.6" of backspace, and that's rim dependent. Mustang Bullitt rims start to have issues around 5.6-5.7". I know of one car that was running 17x9's with 6" of backspace up front that was road worthy, but that was with Cobra R rims.
If all you want to run is 235's up front you should be ok with what you have, but keep in mind any brake upgrades or anything else down the road usually widens track width. And the wheel openings are pretty tight on the lower front corner for Barracuda's, so the more backspace you have the less likely you are to have interference there. If it were me I'd send them back and get the 17x8's with 5.5" of backspace, run the 245's and not have to sweat the fender clearance. But that's just me. It's a lot easier to add an 1/8" spacer if things are tighter to the suspension than you want than it is to cut/roll/push your fenders if you need an 1/8" on the outside.
In the back you can fit a 17x9" on a Barracuda, with anything up to about a 275 with the stock spring locations. You've got an A-body 8 3/4 that's been converted to BBP I take it? You should want a 17x9 with about 5" of backspace, based on your measurements that would center the rim in the rear tub. I'd be looking for a 17x9 and 5" to 5.25" of backspace, same theory as before. You don't need as much clearance to the springs as you do to the quarters, and an 1/8" spacer is easy and won't cause you any problems if you need it for spring clearance. But if you're too close to the quarters you need new rims or smaller tires.
