Thread: 402 BBC deciphering help needed

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To all the educated guys out there that understand engine codes, I'm in desperate need of finding more about my motor. The numbers I was able to pull off the block are 11C181726 and TO621CLB. These are the ones I found on the front passenger side of the block.

So far I the only info I have found is that it was built in the Tonawanda factory on June 21 and could be an early 70's. Is there any way to find what car it came out of and what year it is? Any information is greatly appreciated.

I'm leaning to believe it was a 1971 Chevelle or Monte Carlo but not completely sure.

Well----Since the new models come out in the fall(sep/oct) and it was made on Jun21 it is a probably a late 70 by the time it got into a vehicle

What specific do you want to find out----I have casting/forging manuals from aer around here but haven't ever found a reason to use them-----------with so many aftermarket cranks/rods/heads those original numbers don't mean much to what I do-------

I'm trying to put the components on the block such as the alternator and P/S pump and what not but not having luck ordering the right parts through summit. I figured if I had the type of car/truck and year it would be easier. All I know is that it has a long water pump and only certain brackets will work. Thank you for the info you provided.

From the NastyZ28 list, that "CLB" code points to a '71 or '72 Chevelle, Camaro, Monte Carlo or even full size Chevy - all came with the 402, so it only narrows it down to the year and not a truck ... Decoding Big block Chevy engine suffix codes and stamped numbers: AAA - CTB

Thanks Rspears, I was afraid that was the answer. No other way to narrow down is there. If I were to order parts I could just use any of those models/years you listed to find the right parts correct? Thanks again!!!

'71 was still high-compression. '72 was in the toilet.
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Originally Posted by MasnarT

Thanks Rspears, I was afraid that was the answer. No other way to narrow down is there. If I were to order parts I could just use any of those models/years you listed to find the right parts correct? Thanks again!!!

Seems right. I'd call Summit and ask them to run the numbers on all of those years/models and see if they line up with consistent numbers for the same bracket across the models. Like compare the '71 Chevy, Monte, Chevelle and Camaro and then the same for '72. If they all show consistent numbers for say, the alternator bracket you should be safe. You might even be able to use their on-line catalog and confirm it yourself.

Originally Posted by MasnarT

I'm trying to put the components on the block such as the alternator and P/S pump and what not but not having luck ordering the right parts through summit. I figured if I had the type of car/truck and year it would be easier. All I know is that it has a long water pump and only certain brackets will work. Thank you for the info you provided.

http://www.summitracing.com/parts/gm...5697p/overview

Is this the alt bracket you have?
I keep getting booted off the net so I couldn't get the power steering pump info.
If you end up at a u-pull-it, get EVERYTHING associated with it-- nuts, bolts, washers, spacers, etc. & don't lose them!! LOL!!

Originally Posted by rspears

Seems right. I'd call Summit and ask them to run the numbers on all of those years/models and see if they line up with consistent numbers for the same bracket across the models. Like compare the '71 Chevy, Monte, Chevelle and Camaro and then the same for '72. If they all show consistent numbers for say, the alternator bracket you should be safe. You might even be able to use their on-line catalog and confirm it yourself.

I will be calling Summit soon to ask these questions. Great idea! I might try the online catalog this evening first. Thank you!!

Originally Posted by t-top havoc

http://www.summitracing.com/parts/gm...5697p/overview

Is this the alt bracket you have?
I keep getting booted off the net so I couldn't get the power steering pump info.
If you end up at a u-pull-it, get EVERYTHING associated with it-- nuts, bolts, washers, spacers, etc. & don't lose them!! LOL!!

No it's March performance bracket. I ended up using half of the supplied bracket with a bbc bracket I was able to find at a junk yard. I don't like the look of it but I just want to get the darn thing running then ill work on making it pretty.

The PS bracket I purchased is part number 20150-09-
March Performance Front Mounted Power Steering Brackets 20150-09 - Free Shipping on Orders Over $99 at Summit Racing
I'm getting stuck at the first bolt. Instructions say that for older pumps may require to drill out make it bigger but there are threads in there and I bought the water pump new from summit. How is it going to stay put if I drill them out. Instructions don't go into detail. This will be another question for them.

I'll post a pic of what I'm talking about once I get to my comp. and learn how.
I do appreciate the insight!!! This project has been sitting long enough.

Well just found out that the rear brackets have threads. I just need to drill through the pump with a .406 drill to get the bolt through. I'm very new to this so thank for for having patience!!! Will be doing this tomorrow. I'll let y'all know what I get accomplished.

I had posted the engine specs of what I was told when I bought the motor a long time ago. This is the link to that page.

402 BB and TQ Converter Questions

It's been too long of a project.

Thanks again!

Torque converter--
Oops
Going to page linked