Driveshaft size for a 9" lift

[Doster]

I have a 79 351M and am wanting to put a 9" lift on it. I was wondering if anyone knows what size driveshafts I need????

 

[79rag]

i have 9" skyjacker coils up front and did not do any thing to my drive shaft works good have had no issues

now the rear i couldent tell you cause i put a 60 in and had to shorten it