More more stability !! Help

[baddaw]

Hey guys,

I started my project with an 1980 stepside GMC(completely stock), took off the 350 and swapped it with an ls1, changed the gear ,radiators etc...

Now for my future upgrades, what I want is that I can go 140 miles with a more safer and stability driving

The most I got is 110 miles, at such point theirs a lot of vibration and is kind of scary and had to slow down.

So any suggesting abt how can I keep it goin smoothly and more stable at that kind of speed ?

I will be posting some pics of it soon

[andrewmp6]

The vibrations can be anything from the driveline suspension wheels you get the idea.Have you lowered the truck any?Are tires new and balanced?Have you had a alignment done on it ever?If you have the driveshaft made was it balanced?