1980 rear axle interchange
 

I am doing the 5.0 engine swap in my 1980 ls. which has the open rear. I want to use a LSD carrier and have access to a 1981 gsl ,LSD rear. Are the bolt patterns the same? Can I drop the 81 LSD center section in the 1980 housing? I have read that the 1979-80 housings will not support the 1981 LSD center section but I haven't been able to find out why. I really don't want to swap the complete rears and deal with brake lines and e brake,master cylinder and proportioning valve replacement .

Can anyone tell me if it is possible to just use the LSD gear carrier with my original 1980 drum brake rear. I have cross checked the seals bearings and they seem to be the same??