yz 250 big bore kits, maybe swap to a tri z?

[pcs]

i see that esr is making a big bore kit for the yz250, im not sure what year yz top ends swap with the tri z so i thought id just post some pics of what esr is working on for the yz250. ill let the link explain everything.
http://www.eddie-sanders-racing.com/product_p/yz250%20325%20kit%20big%20bore.htm

[zmpolaristech]

After my recent dealings with ESR...I wouldn't purchase it if it was a direct bolt on (wich they aren't).

[RIDE-RED 250r]

http://www.3wheelerworld.com/showthread.php/16277-parts-that-inter-change-with-TRI-Z-250

Says here that '85 YZ250 is a swap as well as "other years"... Not sure what is included in "other years" but I would be surprised if '99 and later would bolt up....