The m110 engine manual has pages and pages of modifications recommended for this carb... also check the TSBs ... which also have suggestions... plug your car into these sites for the names of the tsbs which apply....

http://www.nhtsa.dot.gov/cars/problems/tsb/central2.cfm

http://alldata.com/

I think a Weber sounds good as a replacement...sometimes things came from the factory that are not worth the time and money to keep going 25 years later.... maybe this is one of those times...