Well, partly because I like the simplicity of the M103 engine and also I have a Sportline kit that I bought for my totalled 86 that I want to install on the next car. I don't think the pieces are the same on the 93 and newer cars. Lastly, price is a factor. If I can find a low mileage 90 to 92 I think I can get it a bit cheaper than a later model.