I've got a 37 with a 261 and I believe we both have a mechanical bell crank set up for the throttle. I have had trouble for years getting mine to work correctly. The problem is partially due to running two carbs with a partially homemade linkage set up. The only solution I ever found was a bigger spring, too! Still I, too, had to "blip" the gas pedal to slow the idle. I finally rebuilt the throttle linkage using ball joint ends at the bellcrank and the carbs along with a bolt through an eyebolt at the end of the of the throttle shaft where it attaches to the bell crank. Now I have a smooth operating throttle with a normal off the shelf throttle spring, but I had to reinvent the stock one to get it to work right. A rework may be in your future.
Joe
