Combines Differences between 6600 and 6620

longer straw walkers, whole lot more power. Concaves will interchange. 6620 still costs more at a sale, though.

150" walkers vs. 120", 14 bar concave vs. 13 bar, concave extends to below rear beater on the 6620, 145 hp vs. 110 on the 6600 (unless the 6620 is an older gear drive model),plus alot of minor things!

my book says hp is 156 on my 6620. The (3rd) concave I put in last summer will bolt in 6620 or 6600. The concave differences you mentioned were only on the oem and not on replacements and they don't help any anyhow. Would really need a larger clean grain elevator to use all it's capacity in dry corn.

Hello Greenstrat, My brochure tells me that a 6620 (gear) is a naturally aspirated 120 hp 466CID while the turbo hydro model is 145 hp, but this is the original series machine and NOT a Titan II, so maybe the difference lies there. You're absolutely right about the concaves, though. In fact, I could harvest higher moisture corn better with the old style (13 bar) concave than the original 14 bar in my 7720.