Valve Lift Mistake??

[Samracing7]

I'm going with a comp cam K68-293-4 cam

Intake Duration at 050 inch Lift 218
Exhaust Duration at 050 inch Lift 226
Duration at 050 inch Lift 218 int./226 exh.
Advertised Intake Duration 262
Advertised Exhaust Duration 270
Advertised Duration 262 int./270 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.493 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.512 in.

NOW.......I have cam accross a set of 1.7 BBC roller rocker arms for....well free. I would really like to use them. With those rocker arms my lift is going to be .590 in. The cam kit comes with stock springs. From what i have read on here, that will be too much lift!

What do I need to run, I.E. springs/retainers to use this cam and rocker arm set up? Does anyone have some good info about running chevy valves?

Thanks again.

[4.whoa]

Lift should be .523/.544
stock rockers are 1.6
I recall reading about someone using chevy rockers(not on this forum), but it was a long time ago. IIRC it took a bit of modification.
Chevy valves get used a lot , just don't go much bigger.

[Samracing7]

I thought that the stock were 1.5! That explains why 1.5 SBC arms didnt even come close to fitting!

That makes me feel a little better!

Do you think .544 is too much for stock springs?

Thanks

[amcinstaller]

not sure if youve seen or knew, but if thats your plan get the CL68-239-4, not the K68-239-4. the lifters and cam will fit the 4.0, but the rest wont.

[Samracing7]

For my sake I kind of hope you are wrong! I've already ordered the kit from summit and should be in this week.

Why will those springs in the kit not work?

[SilverXJ]

He isn't wrong. The springs are meant for a 4.2L head. Won't work on the 4.0L heads. I wish Comp would fix their shit.

[Samracing7]

Yeap your right........comp didnt fix their shit!

I heard comp was going out of buisness?

[Cheromaniac]

Lift should be .523/.544
stock rockers are 1.6
I recall reading about someone using chevy rockers(not on this forum), but it was a long time ago. IIRC it took a bit of modification.

Make that A LOT of modification. You don't need 1.7 ratio rockers with the CompCams 68-239-4. Stick with 1.6 ratio and get the Mopar Performance P5249464 valve springs with P4452032 retainers and P4529218 keepers.

[SilverXJ]

Is this what you were thinking of: http://members.tripod.com/~Mojo_Page/Rokr1.htm