I will have to second Nick on this.
Stats and Specs mean nothing unless you have someone who understands.
Buick engines are a little different then the small block from ford and chevy.
I have tried a reputable machine service, told them what I wanted and still had to redo.
On the same token I also assemble all my engines to my sepcifications and so far have had no issues. This takes time for me to check and double check but it has worked.
Unless you are familiar with the quirks of a particualr piece, it is hard to do it correct. Buicks are not done everyday by very many people so some of the quirks are overlooked.
I recommend a good builder familiar with your particular setup. Sometimes the extra paid up front saves in the long run.
Not sure if this helps.