thanks for the tip guys.
The tires are M/T 29.5x10.5 x15. I've tried tire pressures from 12 to 14 psi.

Dave Stillie
'73 Swinger
5.7 Hemi, 88mm turbo, powerglide, cal-tracs & 8 3/4
Mega-Squirt EFI
[email]8.93@149
[/email]