440 cam choice

[dodj]

Rocker arm ratio is a way of altering lift? Like, if 1.5 is stock, a 1.6 will give you a bit more lift with the same cam?
Sorry if the questions are stupid, but I know very little about engine building. Gonna try it soon though. 

[HP_Cuda]

That would be correct. Say your lift for your cam is at 505 at 1.5 rockers and you go 1.6 you will get something like 530-535 lift or thereabouts.

You have to pay VERY CLOSE attention on P2V(Piston to Valve clearance) issues or kablammo!

This is a simplistic explanation but .....

[73EStroker]

If you only require 1.5 ratio and want longevity why not go for the Crane 273 ductile iron rockers like I did with lash caps. I also used the thicker Mopar rocker shafts and Muscle Motors hold down kit. Seems to be a reliable valve train so far with a solid Lunati cam underneath.

[Chryco Psycho]

Rocker arm ratio is a way of altering lift? Like, if 1.5 is stock, a 1.6 will give you a bit more lift with the same cam?
Sorry if the questions are stupid, but I know very little about engine building. Gonna try it soon though. 

Exactly , the cam lift stays the same but with a 1.6 ratio rocker you gain approx .035 lift , if you have pistons with valve reliefs you should be ok , if you have true flat tops with no relief the valves may hi tthe piston , either way you need to know the clearance , I have a ..580 lift cam in my engine with 1.6 rockers so the true lift is .620 - lash so close to .600 net lift

[dodj]

If you only require 1.5 ratio and want longevity why not go for the Crane 273 ductile iron rockers like I did with lash caps. I also used the thicker Mopar rocker shafts and Muscle Motors hold down kit. Seems to be a reliable valve train so far with a solid Lunati cam underneath.

They are more expensive than the PRW stainless rockers, do you think they would be a better choice?

[cudabob496]

I'd talk with the cam manufacturer also. wanna make sure you don't have too much duration for
your compression ratio.
I've had Crane Gold rockers on my 496 with a stout solid roller for 10 years. No problems so far, and the
valves rarely need adjusting. I think the open spring pressure is about 475 pounds.

[dfark]

My engine and drivetrain will have about the same combination as far as gear ratio 3.55 and 4 spd,  except I want to use a solid cam/flat tappets.  Any thing close to the 303 cam in a solid configuration?

[Chryco Psycho]

Yes , I don't have my Lunati catalog handy but it is online , you need a bit more duration to compensate for the lash with a solid cam but Lunati has a number of solid lobes specifically for Mopar that I generally choose from , you will be able to get more lift at the same duration with a solid cam so as long as you have proper clearance you can get a  killer cam made .

[cudabob496]

I think it was the old Mopar Engine Builiding book from about 12 years ago, where I read
1.6 rockers were a no-no on big blocks. But maybe times have changed, and that was for
otherwise stock components.

[HP_Cuda]

Correct, the advancement in spring technology has made this a reality.

I think it was the old Mopar Engine Builiding book from about 12 years ago, where I read
1.6 rockers were a no-no on big blocks. But maybe times have changed, and that was for
otherwise stock components.