Need help id'ing a bbc

[ofnaman]

I am in the process of rebuilding my big block and I cannot seem to find a definate answer on if it is a 396 or 402. I do not have my measuring equiptment with me and I was planning on picking up the re ring kit tommorro. The casting # on the block is 3969854. All of the info I can find on it say's it's either a 396 or a 402. It is a '70 and the tag in the glove box say's it's a 400. I was under the assumption its a 402, but now I'm unsure. Also if it helps the head casting # is 3975950. Also the rod bearings are from '69. Thanks in advance.