Ok, never heard of them referred as a V10. Is it factory TBI? I worked on a 87 V10 that was 350 TBI, 700R4 and 4x4. It was kind of the new motor and trans in the old chassis. As you can guess the 700R4 was dying. Huge truck junkyard had only a few good 700R4 trans left. They sent one with pink fluid, it shifted Ok despite some moisture. The 87 305 2wd trucks were Qjet and 700R4 trans from what I saw.i'm sorry i should have been more clear, its a 1987 GMC V10 --- which is a 1/2 ton 4-wheel wheel drive truck... the transmission is a custom built ST+ by Phoenix Transmission rated for 550HP, i believe the weakest link is my factory rear axle haha.