No you won't
I then swapped in a 360 in 05. I have 38K on the 360 now and my only regret is I didn't do it sooner.
I gave up about 1.5 mpg; 19ish around town with the \6 to 17.5 with the 360 and one mpg on the hiway 21-22 with the 360. BUT, I gained about 180 HP from ~190 to ~370.