I recently had another rod failure in my fresh motor.Machine shop had done it twice for same problem. Said it has weak rods, so they think i should put rods in it.I don't want to take it back to them even tho they will cover all maching,and parts.Except i will have to pay to put rods in it.So my freind Walt Judy found a 84 gn motor locally rebuilt not assembled yet.( built by someone he knows)It has a set of 30 over wiesco pistons,stock rods and a stock crank.Question i have is what is the difference from 87 to 84 block, know no oil return in 84 block but what else is different?Or am i better off letting them go thru mine again,and pray it don't fail again.Both times i have had less then 1000 miles on it before failure.