John Deere G flat head

[Anonymous-0]

I want to put a flat head (F486R) on my styled G. It has a stock crank in it and is bored .090 over. I know there is a increase in the conmpression , but can anyone tell me what kind of horsepower increase can be expected with a flat head? Will a regular JD G headgasket hold or is another head gasket type needed? Also, will the starter handle the compression or is a gear reduction starter needed? Thanks for any input.

 

[Anonymous-0]

I have a G with the 486r flat head .125 over using a standard head gasket.This head will really make your G come to life.With the compression releases opened on start a good stock starter works fine.Make sure that you also are using good cables and have a good ground as well.I have run this G for pulling for 12 years with not a problem.So go ahead and get yourself a flat head new head bolts and shorten your push rods up and go pulling.I would also recomend to put a new cam (pulling grind) in as well while your into the old girl.You can do a lot of things to a G and get HP increases.You cant run pump gas anymore once you bolt a flat head on.Increased compression= increase to octane of fuel.

 

[jonathon munoz]

I am installing 486 head how do i shorten push rods? GWIZ can i get your email for some more questions?