What should I expect from 450hp?

[QUOTE=" I know.....let me guess. You're not gonna put 3.91s or 4.10s in it.

I do have a 489 carrier with 3:73’s, had these in with my 340. I was under the impression the extra torque of the 408 would more than make up for the gear change but not sure that it feels like it. I do a fair amount of highway driving[/QUOTE]

Sometimes that's the case.......and even though I said that, it might be worth your while to make SURE your tune is top notch. normally, strokers or larger cube engines kinda "don't care much" about gear ratio. So I think before I went drastic enough as a gear change, I would make sure everything else was right. That said, that 3.73 sure would wake it up either way.