Roller Rocker Question

[95 stanger]

I am in the process of installing a new 331 shortblock that my builder installed a Crane Cam. The intake duration is 224 degrees and .542 lift, exhaust is 232 degrees and .563 lift with 1.6 ratio rockers. I have valve springs with a max. of .600. My question is: Is it safe to use my existing 1.7 ratio rockers or should I go to the 1.6 ratio? I asked my engine builder and he said it's not a problem to go with the 1.7. Doing the calculations I'm coming up with about .598 lift on the exhaust which is real close. I appreciate any advice in advance.

 

[juiced_94gt]

1.6 that what the cam was designed for plus why put that lift to limit the springs...if in doubt but the ed curtis PS3 spring upgrage but if it was me i would do 1.6's oh and i also have a 331 and went with 1.6's on my TFS stage 2 cam.

 

[95 stanger]

Thank you Juiced_94gt. That was what I was leaning toward, but wanted another opinion. Guess I will have some 1.7 ratio Trick Flows with about 150 miles on them for sale.

 

[5spd GT]

.563" divided by 1.6 = .352" lift at the lobe.

.352" x 1.7 = .598" as you stated on the exhaust side of things.

As stated, stick with the 1.6's to help your pistons and valve last