1970 Blazer Granny Gear

[K5Fan]

Hello, I'm new to the site, and glad to be here.
I have a manual 4 speed transmission in my Blazer. I am familiar with the "Granny Gear", being 1st gear, but I never use it unless I'm just using it to move a little bit forward, or teaching my daughter how to drive a manual shift. The only other time I have used the granny gear was in a 1967 C-10 wrecker and in that situation, I used it a lot. On my Blazer, I can let the clutch out at an idle and it will crawl along as one would expect, but I can't get any speed without winding out the 350. I have had other 4 speeds with the granny gear, and I do what everyone else does by starting out in 2nd gear, but then it wants a lot of RPMs to get going and is winding out at 60 mph. The clutch is in perfect condition for now, but if I have to give it more RPMs to get going, I'm probably going to burn out the clutch before long. The 2 gallons to the mile thing isn't all that great either. I wanted to get some input on if I should change out the gear ratio, or look into putting in another transmission. i'm only running the equivalent of 33 inch tires, and I don't know what the gear ratio is now, but it seems pretty high. (The higher the ratio, the lower it is geared) I would like to take this vehicle on road trips without burning up the motor, and drive it around town without burning out the clutch.

Thanks for any help you can offer. I hope I did this right!! Thanks again!