Only had one factory equipped K5 with a SM465,it was a '71 CST...
That truck had 3.73's and the wide gear spacing of the trans didn't bother me as much as it did in my other truck,a '72 K5,that had 3.08's..
I did swap the SM465 into my '72 K5,after tiring of its original TH350 refusing to go into forward gears after sitting overnight for several minutes the following morning..
Those 2 trucks were the only ones I owned with SM465's...drove many others though too..I liked the ones with 4.10's or lower ratios best--until it was time for a long highway trip anyway..
Nvrenuf's truck with 2.73's !..you must have actually been able to use "granny low" as first gear on the street with those gears...

I have 2.73's in my G-10 van and it sucked,worse than the original 3.08's it had that chowed the diff case out..TH350 in it in first will top out just under 60 mph,second about 85,third it wont go over 90,its simply too gutless with a 307 ,two barrel carb ..gets decent gas mileage though,if you dont go over 65 with it..