Ok, I read and re-read, I think you meant if I use the heads and buy the valve train hardware, it pinches the budget and thus is why it's hard to go 10's on 5k. First, cast headed 440's fly into the 10's with a yawn. Second, 10's on 10k would be no fun for the trying as it sounds too easy. I'd rather end up at 11.7 for 5k than 10's for 10k. The journey has been and will be more fun than the trip down the track.