I have 2 cams I have perchased and wondered if there are any firm ID's cast in these cams to confirm that these's are truely GM NOS .. I have the original GM tubes they cam in but we all know this dont meen anything. Again, , one cam is supost to be a 140 crossram cam and the other is supost to be a standard 30/30 170 Z/28 .... there is no 140 or 170 stamped on either cam, not to say restamps are not possable now days....
thanx so much in advance. Jim

PS; I am excited to find this website and hope yall dont mind a newbee easing in....

Heck, dial caliper a pair of the lobes for starters b/c a 30-30 cam will be lobe lift x 1.5 to = right at .485"!

And the 140 should have lift's x 1.5 to be right at .493" and .512" lift.

This will put you in the ballpark and for anything else IF there's no other stampings on the ends, you will need to install them and degree both so you will know for sure what you have.

No easy way about this unless you have access to a "Cam Doctor".

pdq67

pdq67 gave you some sound advice, but there may be other ways of identifying what you have. There was a series of posts within the last month or so that dealt with this same question. Check both cams for numbers that are actually cast into the cast portion of the cam. You should see GM cast into the shaft somewhere. This will at least tell you if you have a cam made by the General. If this is not present then you must look to the aftermarket for some answers.
The GM 140 cam should have a white paint strip on the back surface of the rear cam journal. The number 140 did not show up anywhere on the cam I recently sold, I purchased the cam new in 1970 so I know what it was.
The 170 cam I unfortunately cannot help you with. I have never used this cam in an engine, sorry.
Bill

170 cam? Did you mean 178 cam? What is a 170? The 140 was first offroad design. The 30-30 will have a XXXXX347 casting number.

Bill,

Right about the paint IF you remember this stuff?

I wouldn't mess w/ paint marks and would grab my 6" dial calipers to start with.

And right about mulitiple solid lifter GM cams here, b/c we have the old 283/327, -097 Duntov;

The 327/302, -346, 30-30 .455" net lift; and

The later 350, -178, 242"/254" net lift LT-1 cam.

AND imho don't EVER sell the old Duntov short when you are building a smaller motor!

pdq67

I agree with the caliper check, this is realy a diff issue from my question of these being confirmed NOS GM , I raised this question because of a cam on another website for sale that had 1170 stamped on the drive portion of sellers cam pictured on his sale. I have never seen these stampings before and quetion his sale item being NOS GM. Correct information is vital to buying and you folks are great.Thanx a ton to pdq67,Gary L and sbcBill for yer input. Any more input would be great if available..

Jim

My only concern about checking a cam with a calipers, brings me to a question. How can you be certain that the center of the lobe is the center, of the cam ? I have seen people, buy a larger cam, and try to compare them this way. I didn't think you could compare them this way. I would think, that you could only measure maximum lift, from the cam bearing surface and then add 1/2 your diameter of the journal ? (for lack of a better word)