Mike,
I use Automotive Machine and Performance in Philpot, KY (just outside Owensboro, KY) to build my 455 Buick motors for both SS and Top Stock. These guys build Buick engines 365 days a year and usually enter a Buick engine in the PHR Engine Master's.
Ask for Mike or Bobby, 270-729-5556
www.automachperf.com
PM me if you have any specific questions.
Tom