Ok i've searched through the forums, and trying to confirm before i take back on the road.

1. In park revving engine, no vibration (whew)
2. Replaced rear u-joint at rear axle, front at transmission was good
3. even in neutral the same symptoms exist.
4. No matter what gear the vibration was the same

ok for the symptoms

1. under 25 the blazer and engine purrs like a kitten (a big red gas guzzling kitten but still)
2. Once i reach 25 the vibration starts
3. once i reach 45 it's real bad
4. once i reach 60 it kinda smooths out to what it was like at 25 and 30

now i think it's the tires, but i can only afford one more repair until the end of the month (only get paid once a month) and this thing has to get me to work for 8 more days this month so i was thinking

could it be

1. tires rotated and balanced
2. hub bearings
3. rear differential
4. anything else?

any ideas would be awesome, any questions i'll be checking the forums all day. I get one more shot at one more repair and i gotta hope it works. if you got any questions, i'll be more than happy to run outside and try something.

 

Get your tires checked and make sure they are balanced.

 

that's the one fix up on the list, unless someone thinks i should do something different, i swear it feels like tires outta balance