I have the 1218's on my heads, rated at .600 lift, i am putting on a set
of 1.8 rockers and it will change my exh lift to .609, do you think i will
be ok or will i need to change them ? just put them in last month with
the new cam.

 

They're rated for .600 and you want to run .609. Not to mention the higher ratio rockers will in effect change the ramp rate of the cam lobes and make them more aggressive.

Change them.

 

Yup, you risk coil bind and fatiguing the springs early. Are the heads ported enough to have flow gains above .550 lift? If not, you're running high lift rockers for no reason.

 

I am trying to make this cam work better for my 5.3, Comp screwed
me on the recommendation for a cam on a VVT eng. this cam is for a
L92 6.2 with sq ports. I have 799 cath ports on my 5.3. the dur on the
cam splits is 210/224 not very good for me. made to fix the weak
exh flow on the 6.2 heads. I asked around for a easy fix and was told to
use a 1.8 rocker. to bump up the lift. .556/.568 for more airflow.
to offset the low dur. it's also a 114* lobe C/L

 

Just buy another cam. May not be what you wanna hear but considering cost of 1.8 rockers and that aftermarket rockers are heavier and harder on valvetrain, and add cost of new springs...youre really better off buying another cam. Buy an off the shelf cam, use your pac 1218s and lighter oem factory 1.7 rockers.

 

I agree

 

If you don't want to swap cam or springs, you could crutch it by running the 1.8 rockers just on the intakes. That should give .590" intake lift. Should be OK assuming the spring IH is correct at 1.8".

Keep in mind it's still a crutch, high ratio rockers increase lift more than duration. But on paper the cam isn't that bad for a 5.3 with a stock exhaust system.

How does it actually run?

 

I have LT headers and a full 2 1/2" exh W/an X pipe, i was just
not happy with the dyno tune numbers. 304hp@5700 /313tq@4750
this cam specs 1500-6600rpms, I am losing a 1000rpms.
after 6000 rpms it falls flat on it's *** big time.

 

A cam for l92's will not be a good choice for 799's. The difference in size of the intake valves will effect the duration, the lift and the LSA differently then whats needed for your current heads. That cam is not right for your set up and should not be even considered as an option.

 

I called Comp and they said this is what they sell for VVT cams for
all size eng's. boy did they lie and squirm trying to get out of being
wrong about selling me this cam. now i am stuck with it till i can
save enough to replace it. thinking about a TSP 220/220 cam.
yes/no ? it's a DD that tows on weekends. long trips. stock converter.
mods in my sig.