Estimate with lots of assumptions is 190 - 240 BHP to get 100 mph from a tin top bay. Add a roofrack or a pop top and it will go up significantly. Let's say it's a lot more power than most of us will ever see in our vans, regardless of the scariness of the suspension at that speed.
I once got to 95-100 in a friends prototype bay fitted with a 2.0 16v golf engine, the speedo was a blur, the steering was shaking and my pants were a mess, wont be repeating that in a hurry.
HI there, Had 91mph (satnav) form a 1776, Engle 100, dual 36DRLAs and 'oil' on the speedo with a 2007, Engle 110, dual 36DRLAs. Both engines used reworked stock heads and headers with quiet pack. Cheers, Carl.