Can't you put a 350x head top end on a 300ex I want the 300ex bottom end for reverse. What would be involved for doing this.

 

i have seen it done in an old dirt wheels publication (1997 sometime)....he bored it to a 400 two compete in the open quad class or something......reconed it was a good idea cause of the top engine mount....stopped the vibration.....sorry i can't find the mag to give ya any more info! good luck