If'n you's can get mo of dem 665's for 4 hundo you just let me knowI'm way behind on this. But with 665 1mm more stroke and closed quad ports I would guess they would be ahead of the 6400 stock for stock.
I always wanted to run a stock 665 to my stock 415 quad port 65cc .
I wouldnt even buy a 665 for $400 on my site when they were selling them. = parts and cranks etc.
If'n you's can get mo of dem 665's for 4 hundo you just let me know