If you still have problems then I would have to say that your motor is
loosening up and moving around or you problem is really a flex problem.
If you do come to the conclusion that your problem is flex I have a part
that will help with this. You can visit my web site and check it out.
We have been selling a lot of these parts and people have been very
satisfied with them.
Look under products and you will see a picture of it.
Hope this helps
Loosen the brake. Start the truck and watch how fast it goes! Lower your
idle (just above stall point) then set your brakes.