In Reply to: JD 454 A on an IH 1440 posted by Ag Teacher Dave on January 21, 1998 at 19:02:40 EST:

Deere makes a 17 tooth sprocket to use on the outer drive shaft. They are hardened sprockets so off the shelf weld together sprockets won't last long. The originals on my 653A were 13 tooth. With the 17 tooth sprockets we were able to run at least 5 mph. With a six row head it was stretching the capacity of a 1640, but it worked very well.