G Heads

[Frank, Tx]

I have an F486R and an F551R G heads. Are they interchangable ? Thanks in advance. Frank, Tx

 

[Freddy]

yes and no, they both will bolt on given different studs that is. The F486R is a flat head for an unstyled. I had one on my G , it broke. Changed the studs and push rods. Now I have a F551R which is the correct cyclone head for a 1947. What is the year of your tractor?

 

[Lon in NE]

That being said, pullers put the unstyled flat-head on the later G's to get a higher compression for pulling. It always gets me to go to a pull and see a "stock" styled G with the unstyled head. I realize it's a Deere part and it will fit, but it isn't stock in my book.

Lon

 

[G Fever]

Lon,
I have been told that the John Deere dealers used to put flat heads on the G to convert them from all fuel to gas, still using the all fuel pistons in them. And some of them use to change out the all fuel pistons for a set of gas pistons, using the cyclone head.

 

[Mike Aylward]

I have been told that there was an over the counter kit that would convert a G to gasoline. It never was in the parts book but apparently was available with the factory's blessing. It consisted of a flat head, cast iron gasoline pistons and push rods unique to this conversion. I have one of these conversions on the G I have. All of the parts except the push rods are listed in the parts catalog. The flat head is, of course, listed with the unstyled G and the gas pistons are listed with the later styled G. The push rods, however, are nowhere to be found. They look very much like 70 push rods but I can't confirm that. Mike

 

[Radiator Bolt Man]

One has to wonder why Deere didn't actively promote a gasoline conversion for the styled "G" tractors. Farmers would have been tickled to get the added punch! We never owned a "G" tractor on the farm (only 140 acres), but from what I have gleaned - the tractor was just a tad on the light side when put up against the Farmall "M". That alone (if so) would make me want farmers to have the added punch if I were their local JD dealer! (PatB)