John Deere Unstyled G Block

[twocylindernut]

I have a 1939 unstyled g john deere with a cracked sleeve in the block. It is the F485R block. Does anyone know if the F550R block will fit in a unstyled tractor or not?

 

[Anonymous-0]

yes it would be a direct bolt in

 

[Earl-IL]

I think it is 1 in. shorter than the F48R block.

 

[JD720]

It will bolt right in but keep in mind you will increase the compression due to being shorter. Might be pretty hard to start by hand without adding a starter.

 

[twocylindernut]

If i use the late block will i have piston clearance issue with the piston tops and the valves. i have a set of factory flat top cast iron pistons that came out of it that i wanted to use. It has the flathead on it.

 

[jd b puller]

It will bolt to the crankcase fine.

Your water manifold on top of the block, gov to carb linkage, lower water pipe, push rods, air intake will all be different.

As stated, shortening the block will increase the compression but not near as much as you might think. If you're using stock US pistons, it will go from about 4:1 to about 6.2:1. Not earth shattering compression, but will make it run a lot better.

 

[Anonymous-0]

The block will work fine check to see if your head will work there is a diff. ??