A surprise under the hood... need some help plz.

[72TealnWhite]

Hello family,

So i bought this truck about 2 months ago..

Long story short , i cracked an exhaust manifold which got my guys under the hood trying to fix. I decided just to get the work done instead of waiting until winter .. and having the risk of doing more damage ..

So i wanted to match up this motor to the truck so i knew what i was dealing with. The shop guys are telling me that this motor has had some work done..

He told me that the cam was new, so i decided to refurbish the heads while at it.

Well , the pistons are .30 larger .. and he said i have good heads .. anyone know of the GM/Chevy 490 heads ?? and he must have bored the cyl, out .30... so am i dealing with a 380 c.i. block? I got two numbers he said came off the block, i was looking for the block casting # to see whats going on. : He gave me two numbers :

"V10Z9TXB" and "CGF338335" are either what i need to find out the details of the block? and 480 heads.. anyone know of these? Thanks for the help
nate