Apology accepted. What Buick are you working on? There were some Weber manifolds made for the '66 & earlier nailheads, and a very few for the '67 & up big blocks. Devon
'63 Buick LeSabre with Wildcat engine. I am just not sure of the best available carb. Webers are easy to tune. But, I do have a Demon on my '75 Celica and it may be even easier.
Your challenge will be to find a manifold before you worry about installing the Weber carbs... Here's a setup for a 401: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=360224865291 Devon