I have recently been informed that the engine in my 70 SS convertable is not a 454 as I had thought for the 7 years I had owned the car. According to the Engine ID# on the block the "CLB" call letters make it a 402(396). I am having a hard time accepting this, so I wanted to post here and ask the following:

Is there anything that I can look at on my motor to know if it is a 454 or 396? For example the location of the fuel pump or something like that which would make it more definite.

The balancer and flywheel have a weight on the 454'd and 396/402/427 do not.

Alos,check the block casting code

You darn near have to get under the front of the car or P/U and finger the back of the damper to feel if it has the dog-knot on it that a stock type, 454 damper has. AND yes, I have crawled down there and checked one or two!!

You can make a liar out of a Dude real quick doing it!!

pdq67

That would explain why the new fly wheel I put on the car made it vibrate and really darn near wobble when I reinstalled the trans. Taking out a trans twice cause you have the wrong part is not cool if the car is only about a foot in the air. Nor is sitting next to Woodward watching cars go by cause yours is in the garage at home. Its hard to believe that those things mentioned above are the only visable, sort of, differences between the two motors! I feel bettrer now. I don't mind having a 402 either.

Now I need to buy some new valve covers, which also works well because they were leaking anyway.

I suppose I should ask what and where a damper is. I am a rookie and have not heard that lingo. Its not like a canooter valve is it? What am I feeling for exactly?

The damper is on the bottom front of the block and slides on the crankshaft. Its round and the bottom pulley for your belt bolts to it. Do what PDQ says and see if there is weight behind it. Kevin

Is a damper also called a harmonic balancer? Every thing in that area seems to be round with no weights anyway.

The damper is also commonly called the "harmonic balancer"

Externally, the 454 and 396 are basically the same, except for small differences such as casting numbers (and the above mentioned balancer)... engines with differing dates may have had differences in some casting features, such as different marks, or different machined areas (the front of the block next to the timing cover is one area that comes to mind), but not really a 396 versus 454 difference... 396/402 built from 1965-1972 (?)... 454 built from 1970 model year and on...

Heads, intakes, water pumps, cams, gaskets, oil pans, etc will interchange (although some stuff does differ on the newer BB's, from mid-1990s and up)...

What's the casting #?

if you put a 454 flywheel on it, and it vibrated like crazy, then you don't have a 454.
but not all is lost- it could theoretically be a 427. but it's probably a 396.
really, in the end, if you are happy with it, it doesn't matter if it's really a 454. unless you paid a premium to get a 454 car- then you got burnt.
but, if you do ever sell it, make sure to point out that it isn't a 454. otherwise, you might be setting yourself up for a lawsuit when the next guy puts on a new balancer for a 454 and it vibrates like crazy.
and why do you need new valve covers? 366/396/427/454/496 (8100 Vortec)/502/572 valve covers all interchange.
or do they say "454" on them?

Crawl under the hood with a mirror and write down the casting numbers off of the rear passengers side of the block, then go here.

http://www.mortec.com/bbc.htm

Also it doesn't mean that it's not a 454 because it's missing the "weights" on the balancer and flywheel. My old car had a internally balanced 454 (obviously it was done during a re-build) But they are out there too! The casting numbers on the block are the way to tell. Checking the casting numbers on the head doesn't help all the time either. You could have small chamber 396/402 (063's 215's etc)heads on the block to help get some squeeze out of her.

I have recently been informed that the engine in my 70 SS convertable is not a 454 as I had thought for the 7 years I had owned the car. According to the Engine ID# on the block the "CLB" call letters make it a 402(396). I am having a hard time accepting this, so I wanted to post here and ask the following:

Is there anything that I can look at on my motor to know if it is a 454 or 396? For example the location of the fuel pump or something like that which would make it more definite.

CLB is a 1972 402ci engine. As far as having a hard time accepting the fact that you have one great big block and not the other I'd say get over it. They are both excellent choices. If you are upset because you were lied to when you bought the car, then take that up with the seller. (7 years later probably not even worth a try though.)

If you hate it that much I'll buy it from you and you can buy a 454 core and build one.

And fwiw, SB's!!

The stock 400 SB, (and also 350 motors using a 400 crank), balancer has the bump on the outside whereas all others are round. Whereas the stock 454 has the bump on the back inside like I said earlier.

pdq67

Well better late than never :clonk:
But may help some in the future:)

But my 454 has 7.4L marked underneath #5 & 6 cyclinder on the block.

If the engine pad is CLB it is a 71 or 72 402. The block casting should be 3999290 and if the original heads are on it they should be 3993820, 3999241 or 6272292.

that cast marking on the side of the block started sometime in the 80's, I think.

Yep, post the casting numbers located on the trans flange.

Or pull a head and measure the bores. 402's have a 4.124 bore and 454's have a 4.250 bore.