new brakes issue

hi

well i bought some discs and pads for front and rear they came yesterday its a 54 plate sport s type i have  2.5v6

well i fitted the front disks and pads no problem i used new slider pins and boots with grease,well when i put it back toghether the car didnt want to move if you forced it the smoke from the front wheels was unreal! im a pretty compitent i have done the same job two years ago on this car i am wondering is there maybe a slight difference in the discs causing it to foul on something? i put them side to side they look the same.

i am going to try clean up my old discs and put them on with the new pads and see if the discs are the issue if that fixes it im going to try the new rear discs to see if they work otherwise im just going to wire brush the rear discs as they have a lot of surface rust and use the new pads. if the discs are the issue im just going to buy a set of drilled and grooved ones instead

have any of you ever heard of this happening?