The design changes of the 235 that necessitated the lowering of the waterpump etc due to the lower hood designs of the '55 and up GM vehicles also created hood clearance problems for the intake systems. 3754644 was a partial solution as the heat riser box (which the carb bolts to) was lowered giving the oil bath air cleaner clearance with the hood. Dropping the carb lower created clearance problems with the carb linkage. A new linkage was designed to deal with that. I had installed the 4644 on my 54 3100 (57 235 rebuild) and couldn't get the old linkage to work without hanging up. I walked over to the '57 6400 261 to have a look and it also had a 4644. Took the linkage off and it worked perfectly. Compare the pic with your set-up and see the lower carb mount and dog-leg linkage.
~~ Jethro 1954 3100 Back to Life In the Dity Gallery 1951 3100 (gone) / 1956 4400 (still in the neighborhood) / 1957 6400 with dump body (retired) / 1959 3100 panel (in the woods junked) / 1978 Custom Deluxe K10 / 1993 S-10 4.3 / 2004 Chevy Crew Cab / 1945 John Deere H / 1952 John Deere B / 1966 John Deere 2510 / 1967 John Deere 1020
