The Fafnir brand small male rod ends.................... In tension they are quite strong. They were originally designed as aircraft parts and much stronger and fatigue resistant than you might think. Many of the mechanical fuel injection systems for the 1960s used the same brand and size parts also. They are not the cheap zinc die cast rod ends sold by most common speed part merchants in that time frame.
I agree completely with this statement, but I think you missed the point I was trying to convey ; it's not the choice of materials that I was commenting on, but rather the execution of the installation. The manufacture will advise, and it should be obvious, that the shorter the exposed threaded (weaker) stem length the better, and so it is wisely practiced.
The weakest pieces in that picture are the spindles (throttle plate shafts) shafts. The steel E. Weber used was very soft carbon steel in a fully annealed condition which they machined down to very thin cross sections in the throttle bores. Think about coat hanger wire strength. The shafts take permanent twists and bends very easily. The ends of the spindles are very weak. The metal is so soft the levers will damage the shaft ends if allowed to wallow on them.
Yep, and the same is true of many throttle shafts in other applications. I'm not knowledgeable as to any real reason(s) why, but perhaps this is due to the tendency of this small of a round steel shaft, particularly with the machined interruptions in its' profile to not remain adequately strait/true upon heat-treatment; this creating a function problem (and cost to rectify?) with the close fitment of the throttle shaft bore requirements in the body.
This is another reason, although not "correct" for this example, that 'center-pull' linkage, this where the link from the intake mounting to the throttle shaft lever is mounted between the two carburetors rather than as depicted acting at the end of the set of two, as this reduces load in length and the tendency of the shafts to adopt a twist, this resulting in the offsetting the throttle butterflies in seating and the particularly sensitive to tuning, initial timing of position in rotation.
Only few that I know of have the actual small parts Shelby American installed. Original parts are so rare it is impractical for owners and restorers to use everything original.
And yes, I understand this but my thought is when I see the desperation and expense put forth for say a "proper" date-coded radiator cap, oil/air filter element (we have had customers asking for correct date-coded rod & main bearings even!), then I seem to think the "proper", more visible and significant components can be had, if one truly tried. And as you stated, although perhaps rare as far as being as originally installed here, much of these small items were "buy-outs" from suppliers commonly existing inventories vs. some truly rare one-off manufacturing endeavors.
Scott.