I have 1.7 roller rockers on my 454 12to1 solid roller 660 lift 290 dur. My best time is 11:085 AT 120 MPH IN 1/4 mile I WANT A 10 BAD. would going from graemlins/clonk.gif a 1.7 to a 1.75 or 1.8 help.has any body tried this.

The answer is,,, it might. :D
Chances are it will help on a rat a little with a .660 lift cam as your net lift is actually around .630 if you adjust your valves at .020 assuming you have enough spring to control the valves with the added velocity.

I would try them on the intake & see what happens but be sure you have the room everywhere (pistons, springs, seals etc.)
Kinda depends on what your heads want. It will add about 3 to 5 degrees at .050 without adding anything to the seat timing assuming you adjust your clearance accordingly & put your net lift around .670.

Also, is this a billet or a street roller? You need to watch spring pressures on the crapo cast street rollers :(

thanks for reply i will try this .