for the most part you'll are right about the R154 being bullitproof, but they are known to have thrust washer/bearing problems. the W58 is a strong tranny, I have ran one with over 400rwhp with no problem and at that same time, I have seen people blow up R154's with stock HP. It all comes down to what type of clutch you are using and your shifting habbits. another thing to keep in mind is the weight of the car.