Comp Cams: 270, 262, 260

Without getting too involved in what the lift and duration numbers mean, the 270 will have a slightly higher rpm limit, be a little stronger at the top end, and start its power band a tiny bit higher. A stall converter would be more advisable with the 270, though all three could run without it.

Im in the same boat your in except I am debating betwen the Comp 270H and 268h.

I was dead set on the 270h until I read this article (note the camp is used in a chevy 350 but I still think the article is relevent to sbf too):

here's the article
http://www.442.com/oldsfaq/ofcam.htm

"I had a 350 and went through the same things that you are. My first cam was an Edelbrock Performer. Great cam for driveability and torque, but it definitely likes a set of gears and a bit more stall than stock.

My combo was 3.42 gear with a 2600 rpm stall. I was using an Edelbrock performer intake with a somewhat modified quadrajet. My compression was about 9 to 1, and that is important to factor in when choosing your cam. Performer works good with lower compression ratios like that. Performer also works good in heavier carsn like my 82 Delta two door. The only drawback was that it didn't lope at idle.

Performance with that cam and those gears and that converter was EXCELLENT for a small block in a big car. The car got off the line Really good, and pulled hard to 5000 rpms, and didn't do to bad on gas if I drove on the front two barrels of the carb. If you want to REALLY be able to smoke your tires and put your friends back into their seats, than try that combo. I should also tell you that at first I ran the cam without the 3.42 gears (2.73 is what I had at first) or the 2600 rpm stall, and even though Edelbrock said it would be fine like that, it wasn't nearly as quick. The Performer cam is really a midrange cam, and so it wasn't as powerfull as stock off the line. As soon as the cam got into its powerband it easily pulled harder than the stock 2 barrel cam. The people at Edelbrock (and most other cam companies for that matter) don't want to admit it, but the real powerband is from about 2400 rpm to about 5000 rpm. The cam could hold its own off the line, but just didn't really come on until well underway.

When I went to buy a torque converter, the guy at the high performance shop told me stock or maybe the next step up was the max that I'd want with that cam. Well, an Olds 350 is a short stroke/long rod motor, and everything I read about that combo said that they shifted their power into higher rpms as opposed to the longer stroke/short rod small block chevy motor which, against popular belief, should actually focus more of its power lower in the rpm band (for a given cam combination. Obviously a stock cammed Olds isn't going to make more power at 7000 rpms than a pro stock cammed small block chevy). To make a long story short, the 2600 rpm stall worked GREAT with that cam. I also got a set of headers after I already had the gears and converter, and holy cow did those things help! Olds exhaust manifolds must be really restrictive because I didn't have any Idea I'd be able to FEEL such a huge difference.

So here I am with this great combination, and of course I'm not satisfied. I got looking through some magazines and see an advertisement for Competition Cams. They made a bunch of Claims about their 270 magnum cam, and 90 percent of them turned out to be false. I even called comp cams and talked to their tech people, and they had nothing good to say about my performer cam that had been working good for me for so long. They said their 270 mag cam would work fine with my gears and compression ratio, and they said that I could even use a stock torque converter! I should have known better at this point, because the 270 mag specs out at 224,224 Int/Exh duration at .050 valve lift with .501,.501 Int/Exh lift.

Now, the performer specs out at:204,214 Int/Exh duration at .050 valve lift, and about (not positive on this part) .448,.472 Int/Exh lift. As you can see, the performer is much more mild than the 270 magnum, and I already knew at this point that the performer needed more than a stock stall speed to really take full advantage of the its powerband. But comp cams told me what I wanted to hear: 'You'll really be able to hear this cam idle'. So I bought it. And when I fired it up for the first time, underneath my carport with my good buddy who helped me install it, It sounded really tuff. I loved it!

Then I drove it. I could barely smoke the tires anymore (when in the past I could do it so easily it was almost annoying) and I also had a terrible bog off the line. My times at the track improved by only .06 (thats 6 HUNDRETHS) of a second, and gas and driveablility went south! My performer could have gone faster if I would have bought some better tires to hook it up.

Moral of the story: find someone you trust to help you decide what you need for your combo, and don't let that BAD idle fool you. Torque is what moves your car. Many manufacturers put nothing but Chevy or Ford grinds on an Olds cam. Compare the specs. "

Regarding the Lobe Seperation:
a small lobe seperation (106-109) will -
1. narrow the powerband
2. Move the powerband lower
3. make the idle choppier
4. make more power
5. more mid-range power

A wide LSA (110-114) will -
1. widen the powerband
2. make the idle smoother
3. take away from the midrange
4. produce less total power

There are times to use more of one than the other. It really depends what you want out of the combination. If you want a choppy idle with great performance I'd go with something like a 107 -109 LSA. If you want a smooth idle than use a 112. if you are in between then get a 110 LSA. What kind of exhaust are you running - 1 5/8" header to a 2" exhaust? Stock heads? Stock convertor? Then maybe a narrower LSA is appropriate. What compression? There are just too many variables to list without getting an idea of what you want to do with the vehicle. Do you intend to upgrade the vehicle in the future or are you just looking for a cam to match your current combo?

The main difference in these cams is the lift parameter which increases from cam to cam. I'm venturing a guess those with lift nearing 0.5" will require flycutting of the piston whereas the first cam may be able to operate with flat pistons. I would look at the installation instructions for the three and this may give insight into which is best for you. The cams give you progressively higher high end horsepower.

geegee said:

The main difference in these cams is the lift parameter which increases from cam to cam. I'm venturing a guess those with lift nearing 0.5" will require flycutting of the piston whereas the first cam may be able to operate with flat pistons. I would look at the installation instructions for the three and this may give insight into which is best for you. The cams give you progressively higher high end horsepower.

Click to expand...

Power bandwidths of each cam is given on the Comp Cams web page...although I looked at them, and the range seemed to be (low to high)

1200-5200
1500-5500
1800-5800 respectively...

This is a recollection as opposed to fact, so I will leave it up to you to look at the specification page for yourself.

geegee said:

The main difference in these cams is the lift parameter which increases from cam to cam. I'm venturing a guess those with lift nearing 0.5" will require flycutting of the piston whereas the first cam may be able to operate with flat pistons. I would look at the installation instructions for the three and this may give insight into which is best for you. The cams give you progressively higher high end horsepower.

Click to expand...

I've got flattop pistons that aren't flycut and my cam with about .520 lift is doing just fine.