wishIhada5.0

I have a few questions about the stock heads on a 1990-1993 mustang 5.0, What is the ratio on the stock rocker arms and how much lift can the stock springs take before they bind/break? I plan on using a ford racing cam with 282 duration and .498" of lift with Comp cams pro magnum rocker arms with a 1.6 ratio ( Im assuming they are 1.6 because it doesnt say in the Jegs book)

AdderMk2

you have a 1.6 setup already and i believe that cam will be fine without major modification

gspfunk

The stock rockers are 1.6. I would recommend getting a valve spring kit if you're going to run a cam since you're going to be in there anyway. You might be able to get away w/ it, but the stock springs are only good to .500, so you'll be pushing it.

wishIhada5.0

You multiply the lift of the cam by the ratio of the rockers to get total lift right? If i multiplyied right that combo works out to .768", thats way over the .500" mark, im gonna have to pull the heads to put in new springs and i really dont wanna do that, so im probably gonna find a smaller cam, any suggestions?

gspfunk

No..the lift of the cam is usually given using 1.6 rockers, so multiply the lift by 1.7 and then divide the answer by 1.6. That should give you the lift w/ 1.7's. You'll have to do it for the exhaust side also if it's a different lift than the intake.

wishIhada5.0

so in other words they use the 1.6 ratio as the standard and thats already factored into the lift specs then?