Serial Numbers

[John H.]

Trying to figure out the serial numbers on my 1970. The VIN serial number is 407085, the cylinder case number is 3870010.

I am confused reading the 1970-1972 NCRS Technical Information Manual and Judging Guide 5th Edition 2016.

My car is a March 18, 1970 (C18) build.

On page 84 the guide list a cylinder case number for a 1970 350ci as 3970010, my case number is 3870010.

I bought the car in 1972, who knows what happened between 1970 and 1972, believe it to be all original but the guide has me stumped. Am I missing something?

[Michael W.]

Re: Serial Numbers

It's very common for 8,3,6,0 and 9 to all look similar on cast surfaces so the 3870010 is actually 3970010. That's the casting number of the bare engine case. This is probably the most widely produced engine case ever made for the Gen 1 Chev V8- meaning there were probably millions of them around at one point.

Look at the engine stamp pad on the front right (passenger side) of the engine, just below the cylinder head. This pad should display a derivative of the car's VIN and other assembly info.

[Terry M.]

Re: Serial Numbers

Trying to figure out the serial numbers on my 1970. The VIN serial number is 407085, the cylinder case number is 3870010.

I am confused reading the 1970-1972 NCRS Technical Information Manual and Judging Guide 5th Edition 2016.

My car is a March 18, 1970 (C18) build.

On page 84 the guide list a cylinder case number for a 1970 350ci as 3970010, my case number is 3870010.

I bought the car in 1972, who knows what happened between 1970 and 1972, believe it to be all original but the guide has me stumped. Am I missing something?

Reading casting numbers and worse yet casting dates is an acquired skill, and sometimes those of us who have been doing it for years have trouble. I would wager your casting number is 3970010. The numbers 3, 8, 9, & 6 can be very difficult to differentiate as the mold numbers fill with sand and wear from repeated use. The more important numbers on your cylinder case are those stamped into the right (passenger side) front surface. Right in front of the passenger side head.

[Joe L.]

Re: Serial Numbers

Trying to figure out the serial numbers on my 1970. The VIN serial number is 407085, the cylinder case number is 3870010.

I am confused reading the 1970-1972 NCRS Technical Information Manual and Judging Guide 5th Edition 2016.

My car is a March 18, 1970 (C18) build.

On page 84 the guide list a cylinder case number for a 1970 350ci as 3970010, my case number is 3870010.

I bought the car in 1972, who knows what happened between 1970 and 1972, believe it to be all original but the guide has me stumped. Am I missing something?

John------


I agree with the others; your cylinder case is GM #3970010. Plus, since there never existed a cylinder case of casting #3870010, it certainly could not be that number.

[Kenneth B.]

Re: Serial Numbers

The date tag was changed every day & the #'S were usually silver soldered on. If there was a sticker on the tag it would have pulled the sand away from the tail of the 9 & it would look like a 8.

[John H.]

Re: Serial Numbers

Thanks all, I will go back and take a much closer look and check out the front right cylinder surface.