Starter for Deere 2640

Need to replace starter on 2640 with FEL. Looking around on the internet I find at least three different styles. Straight drive and two styles of gear reduction. What are the advantages and disadvantages of each. Iwould like for the engine to spin faster when cranking. Frank

Gear-reduction starters can crank the engine a bit faster when under a very heavy load, but spin it slower when not. There is no big overall gain, one way or the other. Delco made two versions of the direct-drive diesel starters the biggest one is the best "overall" cranking starter. Deere used to call it the "900 amp" starter; not sure why, whereas the standard starter was the "700 amp." The 900 amp starter has a main housing that is just one OD overall.
The 700 amp starter has two ODs and is smaller towards the rear - i.e. it steps down.

By yourself a $10 pump destroker and any starter will work fine. All Deere tractors with closed-center piston pumps can develop hard cranking problems.

Just about all new starters now come from China (even if bought from Delco). Many of the new gear drives look the same on the outside but come with different watt power ratings. Get specs before you buy. Many brand-new starters around for $100 that replace the Delco two-bolt starters. I've got many and all have been fine.
Got them on my diesel pickup trucks also (Ford and GM).

There are many resellers buying new starters from China on pallets for $50 each and reselling. Subsequently many are buying the cheapest ones. Ask first and get a power rating, since many no longer post those specs.

A few examples of specs:

Original Delco direct-drive - 2500 watts of power.
Newer Delco authorized gear-drive- 4000 watts
Best Chinese gear-drive clone - 3700 watts
Other Chinese clones - 3000 and 2500 watts

Look for a 12V winter starter for a four 2763,
359 or 414 six cylinder Dubuque/Mannheim. If it's
a Bosch there is the standard 3KW and the
larger/better 4W.
I was all set to up size the starter on my
tractor but first installed a chassis return cable
direct from the battery's (-) to a starter
mounting stud. What a difference. Bolted on sheet
metal doesn't carry current worth a darn.

I don't know if Delco Remy has released yet the
mighty MT44 with the two bolt mount.
Here are a couple of cross reference 4KW Denso's
from Mother Deere.

Engine 6359A 12 4.0 AR63341 028000-3971
9702800-397
6.8L PowerTech Plus Engine 12 4.0 RE65817
228000-9020

Thanks JDemaris and buickanddeere for answering my starter question. the OEM starter on the tractor has reliably cranked the tractor to 32*F. Now I must replace this starter (bad armature) and want the tractor to start at least as good as it has in the past. Frank