raceguy

I'm trying to help my uncle so it may take a day or two answer any questions.
He has a 125" ? hard tail altered. No front or rear suspension. I believe it was
built in 1989. Not sure who built it. It now has a small block and glide in it.
Runs 9.30 @ 140. Problem is a pretty bad shake in front end when lifting at
big end. All steering rod ends are new, front tires and wheels are new and have been balanced by two different people. Tried adding 100lbs to front end. No help. I Haven't drove the car myself for a couple years, but he's
describing a steering shake, ( back and forth, not up and down).
It has gotten worse over time. The last time he had it out it was too spooky
to make a full pass. We have checked the chassis for cracked welds etc.
but don't see anything. Maybe need to look closer?
Any help or advise would be greatly appreciated. Thank You.