another option,you could use a full manual valvebody in the tranz to delete haveing the linkage.

get another carb with the biger lever on it

if you can get a junk carb,you can grind the end of shaft to remove the lever from it

grind your carb shaft end to remove the lever

install the new lever and tac weld it back on at the end of the shaft

I have done this to a few early chevy q-jets to put the mopar throttle lever from a mid 80s Q-jet

that way it bolted right on the mid 80s doge truck with the stock 4-v linkage..but had a early non emission q-jet(late 60s to early 70s chevy q-jet are the best ones)

do you want a carter/edelbrock to go on it? or do you want to stay with holley?

after looking I have a 650 carter on the shelf with those 2 holleys also

if you used one of those,it might be able to go with stock linkage fairly ez...