Whats up buddy.
This is my first rodeo with Turbo Buicks so I have been eating up as much as I can when it comes to the learning curve. Unfortunately, a few days after my purchase the engine let loose. I'm in the process of getting her to a builder.
Since no one has mentioned it yet , I'll do the honors.
Probably even more important then whats going into the motor is WHO is building it !!!!!!
No matter how good of a reputation your local machine shop may have, if they are not VERY familiar with THESE motors and knows exactly how to build them, you are MUCH better off going a little further away (if need be) to an experienced Buick Turbo Motor Builder,or even ordering one from one of the well known builders on this site.
These motors are not like building a small block chevy, They are notorious for having unknowledgable builders put them together and blowing up within a few hundred miles or less,(it may even be the problem you just ran into).
Can't stress this enough,get the right builder, + then the right installer,make sure they prime the oil pump correctly before start up,make sure your electrical system and fuel system is all up to par with the rest of the build,make sure it is tuned right + has no knock (Need at least a scanmaster)before you start to really get into the throttle. etc. all things a proper installer will know to do.
Read ,read,read + talk to knowledgable people on this site before picking a builder/installer/tuner.
I'm sure other members can point you to someone in your area.
Getting everything right from start to finish is the key to happiness with these cars,Otherwise you will run into lots of very expensive misery.
Good Luck with the build.