Originally Posted by 69CSHC

I have done plenty of research on this subject but still would appreciate input. This is my take, please let me know if i am fairly accurate. Sorry if it comes off somewhat redundant or silly. But i would like to have absolute clarity on this subject or be as close as possible.
Where and how did you do the research ? There are tremendous over generalizations and only use valve lift.

1968-1980 Olds base 350 automatic all shared the same cam specs ? 1977-1980 just had a different part number ? 1968-1970 base 350 automatic 2bbl or 4bbl all share same cam ?
1968-1970 350 had a total of 3 different cams .474 lift (W31) .472 lift (stick) and .400 lift (auto) ? Which means my engine has weakest cam for 350, and there was no lesser cam option, ever ? All stick shift have superior cam, 3 or 4speed ? Obviously W31 is superior to stick cam.

The only major advantages my engine has over the 1976 version power wise is, higher compression, better heads, and no factory required pellet type catalytic converter ?
Valve sizes could be different. Carburetors and jetting also contribute.

If you take 3 base automatic Cutlass and swap all 3 different 4bbl version 350 in. All else 100% the same. Absolutely no other difference in drivetrain, etc, to take advantage of more aggressive cam. The higher number lift will win in a 1/4 mile race no matter what ?
Can you make your question more precise ? I am confused what you are asking.

Originally Posted by olds 307 and 403

The manual trans cam is a nice upgrade especially if you have the higher compression motor. It would allow a more aggressive timing curve with it's 216/217 duration. Add a 2000 stall and 3.08 or better gears and it will br night and day better. I run a very similar cam

Originally Posted by OLDSter Ralph

Originally Posted by OLDSter Ralph

Can you make your question more precise ? I am confused what you are asking.

Originally Posted by 69CSHC

Sure, if i could swap my engine with a manual version or W31 version. Will i feel / see a significant performance increase (1/4 mile) without doing other things to drivetrain?

Originally Posted by 69CSHC

Conversation, internet, blogs, magazine articles. Used only valve lift for simplicity.
While valve lift is important and can vary, it isn't the best to use.

For example Motor Trend 1970 tested a 3sp std Rallye 350. (I was under the impression that it shared my same cam, i was wrong.)
" The camshaft is new to the 350 CID engine, a neat compromise between the stock 250/264* duration cam and the hairy 308* cam of the W31. It is the stick used in last year's manual-shift 4-4-2, which has 286* of duration and 58* overlap with a lift of 0.472 instead of the stock 0.400 inch. Valve spring dampers are also used. The combination has proved such a nice one that it may be used on all manual versions of the L74 engine for the rest of 1970." Motor Trend February 1970
250/264, 286, 308 degree cams are far more valid to use for comparison....although, torque converter, gear ratio and transmission combinations can allow a cam to work as intended.

Sure, if i could swap my engine with a manual version or W31 version. Will i feel / see a significant performance increase (1/4 mile) without doing other things to drivetrain?
If you swapped to the 286 degree cam, assuming you have the 250/264 cam would increase performance if the carb jetting was ok. The 308 degree cam would NOT increase performance because you need a "looser" torque converter and lower rear end ratio (higher numerical). The W-31's were required to have 3.91's when ordered, I think.

For example Motor Trend tested a 1968 Cutlass Supreme, with a virtual carbon copy of my cars options except it was only a 2speed automatic, 17.44 @ 80 mph.
The two speed tranny was not good for performance......in fact they were terrible.

My car is almost 10 mph faster mainly because its 3 speed auto (has better 1st gear)
The three speed has a better spread using three speeds instead of the two speed. The three speed transmission keeps the engine in the power band in each gear better than a two speed transmission.

and partially because its dual exhaust. (Not sure about that 68 but it should be single exhaust ?) So go package/setup is most important in this case. I'm not sure that the 68 even with an additional 50 hp can catch me ?
Dual exhaust can help.

I guess i am just trying to better understand the balance between power and setup for maximum performance.
Conversations, and blogs are just "opinions". Motor Trend Magazine, while was a great magazine, its focus was not horsepower and 1/4 mile times. The cars that were "loaned to the press" were not always what you got from the assembly line.

Originally Posted by Fun71

If you plan to change cams to increase performance, look at aftermarket cams, also. There are some really good grinds available that are better than the factory designs.

And as for the best bang-for-the-buck performance mod, lower rear gears top the list.

Originally Posted by 69CSHC

For example Motor Trend tested a 1968 Cutlass Supreme, with a virtual carbon copy of my cars options except it was only a 2speed automatic, 17.44 @ 80 mph.

Originally Posted by Fun71

If you dropped a W-31 engine in your car without any other modifications, it would be slow off the line and not have significant power until 3000 RPM. The W-31 camshaft was a radical high RPM grind, made very low vacuum due to the long overlap (think no AC or power brakes), needed low rear gears and either a manual transmission or loose torque converter in order to get off the line.

Originally Posted by JohnnyBs68S

That's depressing, that was my car in its original configuration (442/2 = 221: 2bbl, 2spd, single exhaust). Its now a 242 (w/ a 3.90 posi replacing the orignal 2.78 open), and is definitely quicker off the line (not sure what it would trap at).

Originally Posted by 69CSHC

I understand, and hear you with regards to going with a newer aftermarket grind, guessing i can get 308 degree type power or better while limiting some of the potential drawbacks that would otherwise need to be addressed in setup.
You might find a cam grinder that will grind a cam to factory specs, because Oldsmobile cams from the factory are not available. I think SuperCars Unlimited and Melling offer a cam similar to some factory cams. I won't recommend either of them because I haven't used them. The original factory 308 and 328 cams were very potent.
A blueprinted, stock W-31, 4 speed ran LOW 12's 50 years ago. That was with a Quadrajet, stock intake manifold, forged stock type pistons, stock valve train, etc. on 7" tires. Now, thats "old technology".

You can use the factory cam specs to choose an aftermarket cam by similar duration and lift. Be very careful when comparing cam specs. There is an "advertised" duration that was used for 60 years or so. This is degrees from valve open to valve closed.

Then there is the "___@.050" degrees duration spec. This came about inthe mid 1960's by Harvey Crane claiming his cams made more power than any other cam with the same degrees. His cams were spec'd at .050" valve lift. Basically it was partly marketing BS. Crane did some testing and determined valve started when the valve was .050" off the valve seat and used this to rate his cam specs. Most cam grinders now list both the "advertised" and "__@.050" specs on the cam card.
Generally, when I see ___@.050" specs mentioned I add 60 degrees and its in the ball park for "advertised" degrees.

OLDSter Ralph
Understood on using the degrees. So it seems that the 286 degree cam is the perfect compromise if i want more power but want to stay factory spec cam without too many other steps.
Any cam choice with more degrees duration will be severely restricted by your 2.78 rear end. Thats probably why Oldsmobile used that camshaft that you have. Without a rear axle ratio change, you won't gain very much. The 285/287 (advertised) degree cam could be a step in the future, but you'll need a 2200-2300 "flash" torque converter.
....Just my two cents worth.

Originally Posted by coppercutlass

I wouldn't do any factory cam. Much better grinds out there. I would focus on building an over all planned out build. I ran 13.9's with a 9 to 1 compression 350 with a comp 260h cam ( very mild) with 73 350 72 7A heads and an edelbrock intake 3.42 gears a th400 ( which eats up 20 hp and a 2200 stall. Engine was pretty much stock. 73 350 and 7A heads. With a performer intake.

Originally Posted by OLDSter Ralph

Any cam choice with more degrees duration will be severely restricted by your 2.78 rear end. Thats probably why Oldsmobile used that camshaft that you have. Without a rear axle ratio change, you won't gain very much. The 285/287 (advertised) degree cam could be a step in the future, but you'll need a 2200-2300 "flash" torque converter.
....Just my two cents worth.