Rear End help....

i have an 85 mustang t-top. i put a rear end ot of an 87 turbo coupe t-bird in it. im planning on completely gutting the rear end and just leaving the housing and putting in all new mustang guts. axles, gears and spool. right now with all the t-bird guts and axles the rear end sits 3/4" wider then a mustang one. now my question is, is it the housing longer or or just the axles? if its just the axles then when i put in mustang ones it'll be normal. but if not, then i gotta get a new.. any insight would help. thanks

thanks...

i do intend to replace all insides with upgraded parts.33 spline axles and a spool with 3:73 gears. i had this rear end on for a while cause i had come across it for real cheap. thats why i had swapped out my 7.5 for this 8.8. but now i need stronger axles and i want to go with a spool. better then having to buy a whole new one. Strange rear ends have an axle kit for a reasonable price, so thats my plan.. thanks for the help