if the 85 has the 10mm bolts it should bolt up. i couldn't use my 79 driveline on a 92 axle flange, because the 79 had 8mm bolts and was different. found a ifs front driveshaft laying around with 10mm holes. removed the flange and installed it on the old rear driveline. works perfect. hey if you measure you drive shafts post your results. I'm going to need new driveshafts after i finish a tranny mod.