Combines 4400 vs 6620

I can run down some of the specs, but bear in mind there is a world of difference between first reverse air flow 4400 and the last 6620 Titan 2. Cyl width 38" vs 44" for 6620. Walker length 120" vs 150" for 6620. Walker area 4559 sq in vs 6593 sq in for 6620. Cleaning area 3357 sq in vs 4887 sq in. Grain tank w_ factory extensions 102 bu vs 166bu for 6620. Engines 4400 could have anywhere from 292 gasser to 329 diesel all with around 95 hp. 6620 has 466 diesel and later ones optional turbo. Power depended on how far screw was turned. Factory says 145 hp. 6620 has optional hydrostatic drive. No comparison between variable belt and hydro. Weight of machine w_o heads about 10,500 for 4400 and about 17700 for 6620. Have to consider what heads you are going to use. Will old ones workIJ Header ht control-- got it or want itIJ length of rows in relation to grain tank cap. Do you unload on goIJ Do you no-til and need reside spread evenly. Will you need more hauling capIJ The list goes on. Parts availability is always going to be a prob with non-current machines. The older ones are harder to find parts for than newer ones. Hope this helps.

Thanks for your help. We are going to look at a 6620 tomorrow. I just wanted to know a little more about the machines beforehand.