[GMCDAC]

That 3/4 ton truck probably does have 4:11's but still should run higher speeds. My '72 3/4 ton GMC also has that ratio. It's a 350 but will run all day at 75 mph fine. Sucks a little more gas than at 55 -65 for sure though.

If you go to a 350 find a set of 327 valve covers and they will look identical! If I remember right the 327 was a 4" bore just like the 350 anyway.

There probably isn't a u-joint in the steering column, so have a helper turn the steering wheel back and fourth just in the "play" range and start studying the steering box and flex joint, pitman arm idler arm and tie rods to see where the steering response reduces or stops moving.

The left front brake is grabbing harder then the right causing that pull, and possibly the LF isn't functioning at all.

That cable could be slapping around so just tie it somewhere and try driving again.

I like both of those greens but go with what you like.