"back face of block to front of water pump pulley 660mm"
If Ive read this correctly this will be shorter with the electric pump? do you know by how much?

T
Ok gearbox to back face of block (inc the adaptor ring) 370mm
back face of block to front of water pump pulley 660mm
total width (inc spark plug leads etc) 600mm
total height 700mm

Just checked out my AW11 shell.
There is around 900mm* between the chassis rails an about 880mm* between the strut towers.
These could be massaged a bit further with a bit of hammer work for another 10mm - 20mm.
Overall though, it looks like 1030mm won't fit without chopping the towers and chassis up :(
 
Can someone measure up an SW20?
 
 
 
 
 
 
* This leaves a small amount of wriggle room for motor movement and alignment. Anything bigger then this will result in the package hitting the body during driving

From memory the outer edge of the gearbox sits under the chassis rail on the mr2 (I had a couple of aw11's)
 
How cheap is cheap?
there is 2 on gumtree for $3500 & another 2 for $4000. Any of them you could prob pull down $1k on those prices - ie auto gen1 sw20 hardtop not exactly sought after!! & you could prob offolad about $1k in parts out of it making a track car (& there's a set of tein coilovers for $250!)
 
price drop on conversion - now $4500!

fyi: http://www.mr2oc.com/showthread.php?t=453400 (v8 mr2 fitting)