I have seen a handful of Tonowanda cast blocks( see comments below for clarification) built as DZ 302 engines. As a matter of fact Kenny P's green vintage certified Z28 was in fact a 388 block.
Let me clarify; 388 blocks are known to be cast at the Tonowanda plant. It is fairly common to have say L48 350/300hp assembled, and stamped TOXXX( Block cast and assembled in Tonowanda).
Now in the case 302 I have seen a handful with 388 blocks, however they are stamped VOXXX indicating they were assembled in Flint. So the question really is was the 388 block exclusively cast at Tonowanda (conventional wisdom)? If that is the case then the block was cast in Tonowanda and shipped to Flint for assembly (not sure that makes sense). Or another theory is that in fact the 388 block was cast at Flint in very, very small quantities, at a specific time period.
Verne to answer your question, I have not seen a DZ 302 with a Tonowanda assembly designation, so at this point I only believe they were built/assembled at the Flint plant.
If anyone has Tonowanda assembled DZ 302 please share the information and provide a picture of the stamping.
The attached photo is a 388 block, which are sans the plug in the front. Also notice the assembly /date starts with VO Flint assembly designation.
