I have the 274 cam on my 331. You won't be dissapointed in that cam. Mine has good idle quality and it pulls like a raped ape. I almost wish I would have went with the 282 cam but I can't complain.
Brand: COMP Cams
Product Line: COMP Cams Xtreme Energy Retro-Fit Camshafts
Cam Style: Hydraulic roller tappet
Basic Operating RPM Range: 2,200-6,200 RPM
Intake Duration at 050 inch Lift: 236
Exhaust Duration at 050 inch Lift: 240
Duration at 050 inch Lift: 236 int./240 exh.
Advertised Intake Duration: 288
Advertised Exhaust Duration: 294
Advertised Duration: 288 int./294 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.555 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.576 in.
Valve Lift with Factory Rocker Arm Ratio: 0.555 int./0.576 exh. lift
Lobe Separation (degrees): 110
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in.
Computer Controlled Compatible: No
Grind Number: FW XR288RF-HR10
COMP Cams Xtreme Energy retrofit camshafts are built to take advantage of the latest cam technology, to provide maximum performance. Whether your use is off-roading, towing, or street performance, there is an Xtreme Energy cam available for you. By using an aggressive lobe profile, these cams provide better throttle response and more top-end horsepower than equivalent cams from other manufacturers, while delivering increased engine vacuum.
trick flow cam specs are listed for 1.6 rockers. the stage 1 cam with 1.7's is .510/.542 with about 3-4 more degrees of duration.
the one listed above is way too wild for those heads. not to mention that those lift numbers are prolly for a 1.6 rocker(which would make that lift .590/.612). your heads do not flow near enough to warrant anything over .550 lift. you also did not state what type of typhoon intake you have.
2ksilvergt---you also have much better flowing heads, so your results will differ.
it is .530int (were it was .499) and .5418int. (542 like you posted) on the .510 exh. side.
The dur. will not change 3-4, you may see some but 3-4 is more than you should see but the speed the of the valve action (off the seat) will speed up and that would take advantage of any good low flow numbers for more power under the curve.
That came being a "retro-fit" kind...I dunno if that will work in a factory roller block? IIRC the retro-fit was for the smaller base circle non-roller blocks so they could use a roller cam.
I still say see what the porter/world would recomend...I am sure they have tested alittle bit. At least to see what they sug. for a starting point. If the exh. side has been opened up that I/E % will more than likely be alittle off now so you really need to know what the porter has to say if you want the best OTS cam and fewest doubts.
i will ask the guy i bought the heads from who ported it so i can give the porter a call. and there is a coworker who's father owns a machine shop who builds performance motors. he has a flow bench. i'll talk to him too
FWIW, in the cylinder head shootout series they did about 3 years ago in the 5.0 magazine, the middle combo was a CHP 331 and they selected a XE274HR cam for those tests.
Go over to hardcore about those "tests", MANY believe they used that cam to make "some" heads look better than they are and make "others" look ok by comp. The flow bench series is prob. one of the best OTB head flow deals done. No miss-matched cam for some heads, no BS, just flow numbers.
I am not knocking your reasoning, just take the mags with a grain of salt they have ad buyers to make happy as well as companies that give them things.
good luck, at least your doing your best to find a OTS cam for your combo instead of going letter cam or just tossing a cam in there.