The seats are ground into the block. No hard seats for the bigger valves in a K series. You will need to go with 1.650" exhaust however to get everything to clean up and seat properly, you might get a little smaller exhaust but not much. I have used 1.8,1.88 and 2.00" with a stock stroke 0.060" over 16, for pulling I had much better luck with the 1.8, and 1.88" than I had with the 2.00" for tractor pulling, the 2.00" would wind up really well but no torque. Without welding considerably you cannot maintain a good port volume size to valve ratio with the 2.00" intake size.
