no i just measured the heads and its 2 inch.also i was going to use them on my 351w and i bolted 1 header from my turbo kit up to the head and it bolted up fine.my kit was made for a 302 and to make it work on a 351w we had to mod a few things.so being that the exhaust ports are raised i didnt want to changed the heads out and then maybe have to make everything else fit once again so i just stayed with the twisted wedge heads