In Houston most all Buick V6 guys use Southwest machine and racing engines. They're main business is race motors but they are very well verssed on the Buick. I highly recommend them.
Sorry about not posting the needed info but I didn't know where in Texas. The owner of Westside Machine is Cleat Kealand, the phone number is 713-465-7996, address is 9100 Emnora, Houston 77080, website is Westside Performance & Machine - Houston, TX - Engine Rebuilding & Repair
I think I posted 'Southwest machine' but Westside is correct. These guys are very good and 'unlike many engine builders' these boys stand behind there work. Rest assured that yer motor will be right and they also do heads and intakes. Give them a call and talk with them. You may get Dave, you'll know because he has a Cajun accent but just tell um Frank Weeks told you to call and they both will know what you have. Oh yea! They can improve yer oiling system also if you ask. If you choose them, you won't regret it.