i have done a Dmax repower my self... same GM std bell housing bolt patter. LBZ(06-07) cam with 4l85 in the chevy 3500 vans. 08 and newer come with 6l90s.. i plan on putting on in my 79 malibu with the T56 behind it and a 13" single disc clutch. Dmax runs a 14.X" flywheel.. i did the swap for about 8k at a need it now pricing... probally do it for 5-6k in a no rush deal.. in stock hard part form.. the dmax is capable of putting 600-700hp at the crank with just tuning.. size wise its same lenght as a LWP BBC ~1" wider and ~2" taller (turbo) and about ~100lb heavier than a iron head BBC
put a 06 LBZ in my 99 C3500HD
as for speed....
buddies 06 LBZ 3500 2wd express van with 4l85 its done 10.6
http://youtu.be/8H94FMG3VFM