If you are switching carbs get the correct TV & TV corrector Brackets.
With the Edelbrock linkage the TV pressure rise will be Low= BAD and can burn the Trans up. Your TV Cable Bracket may be Ok with the Edelbrock.
Eddy >> http://www.summitracing.com/parts/SUM-700203/
Holley >> http://www.summitracing.com/parts/SUM-700202/
You should do a Pressure test.
Are you using the Factory Tach? If so they are famous for incorrect readings.
With 2.73 gear, 26" tall Tire, 3500rpm you should be running 99mph. in 3rd gear
in 4th 141mph. In 2nd gear 61mph.