You will need to check the casting date which is located near the casting numbers and post the stamped information from the front pad to find the year and what car it originally came in. Use the "Tag Team" section of this site.
The front pad has been machined and there are no other numbers visible on this block as it is still in the vehicle. The numbers are definitely 3870010. One other note, the damper is BIG and the heads are "186". Thanks guys.
Do the dates from the heads come close to the block date? Are the valves 2.02 & 1.6? If so, you probably have a 69 DZ 302 motor. Check the crank and pistons for part #'s if the motor is apart. Sounds like a nice engine.
Just for informations sake not all 010 blocks are 4-bolt main blocks.I personally took a 010 motor out of a 74 or 75 malibu and to my dissapointment, it was a stinkin 2-bolt block.Also the 69-70 186 head came large and small valve,and on a variety of cars.I have taken small valve 186s off a 70 monte carlo,and a 69 impala.