the Phoenix’s last ever run in 2003 at Bonneville, set the current record for the Unlimited Diesel Truck class at 272.685 mph! (With a junkyard find ’47 International K-7 semi !)

http://www.ugofadini.com/phoenixstory.html

R.B. Slagle, who thus became the first trucker to enter the prestigious 200 Club. 

For Speed Week 2003 the streamlining was extensively improved by adding a "wing" at the front and a new long tail to reduce the turbulence at the back, somewhat in the style of "long tail" versions of sports racing cars for Le Mans. The modifications must have been effective, because Carl Heap improved on his record again early in the week (272.685 mph)

 

Skip the first 8 minutes 

Or see this WAY too short video that cuts out the semi truck used as a pusher that was spinning tires like made to make speed 

The Phoenix made its debut pass at Bonneville in 1989, running 158 mph. Eventually, the truck went 188 mph, then 212 mph, then broke 250 mph -- and the streamliner record. 

Carl Heap proved just how far a determined team can come with some effort (and a lot of streamlining). 

The truck now resides in Hastings, Minnesota, at the Stagecoach Diesel Motorsports Museum.

First race above, and 13 years later, the evolved and streamlined last race

https://www.jalopyjournal.com/forum/threads/slagle-heap-43-international-detroit-diesel-bonneville-race-truck-tribute-page.526065/