could i get a fourtrax 300 head and put it onto my 86 250 fourtrax bottom end? what parts would i have to change?

 

The head from a TRX300 will fit your 250. You will need to use the cam chain and cam sprocket from a 250. The chain has a slightly different pitch and width than the 300. You can't use the lower sprocket from the 300 to make a match because the 300 lower sprocket will not fit the crank.

KNOWSALOT

 

how much do u think it will cost and would it be worth it?

 

also what parts would i have to change? would the 250 cam and rod work? would i have to buy the complete 300 head?