Hey I wouldn’t cut the bracket off a ‘67 K frame either! Of course, it’s because I wouldn’t ever buy a ‘67 K to begin with, the factory literally made them obsolete in 1968. The ‘73-76 sway bar provision is worth the upgrade to the ‘73-76 K by itself. Better ground clearance, better tire clearance for wide front tires (245 or better).
235’s aren’t wide, and if they pre-dated compound ratings then they were much harder than what you can get now. 275’s with 200 tread wear compounds are not even in the same ballpark as those old 235’s.
As for the 9” spindles, well, there’s plenty of people here that defend them. So they must not have seized up the undersized wheel bearings or sheared the undersized lower ball joint bolts. But hey, that doesn’t mean that other people didn’t. Much like your take on the ‘67 only idler. Awesome, you didn’t have a problem with it. Other people definitely have had issues with it.
And if nothing else, the ‘67 idlers are stupid expensive. The OP doesn’t have to deal with the ‘67 K or idler at all, and there’s no reason to even from just a financial stand point, let alone a performance one.
