Well, there are other minor differences as well. The 029, 029 Super and 290 have smaller jetted carbs compared to the 310/039/390. The 039/390 also has a heat shield included in the muffler gasket, and the 029/290/310 do not. The early 029 and 039 models have the more open style mufflers and the later ones are choked up. Some 310 and 390 saws have decamps and some do not. Also the rim drive was an option on these saws (same one as the 036 model) but most had/have spur sprockets. The plastic had some differences as mentioned above. The 0 models have the screw in oil and gas caps and the MS models have flippy caps. Some early 029 and 039 models had a screw twist locking AF cover and the later models have the lever twist locking AF cover. The later model carbs have limiter caps on them as well.