The Mk1.5 as most aptly named by Deno Plumley regarding his car which has bridged the gap between the two generations of MR2's. he has combined the brute strength of the 3SGTE powerplant in the mk2 with the superb handling charateristics and weight of the mk1. Essentially creating the best of both worlds for dominating at almost all types of motorsports.
The engine swap itself is not for the faint of heart mind you. There are so many things to consider when doing this swap, stuff like; Intercooler location, modifying the axles to fit, motor mounts, electrical, and many more hurdles when doing an engine swap of this caliber. There have been a couple excellent write-ups on this topic, one of them by Carl Crawford when he transplanted a 3SGTE into Ed Farrel's (sp?) Champaign Coloured MK1 and the other by Paul Woods when he converted his red 85 mk1. Those articles can be found by following the links further down the page.
The Proud owners of MK1.5's in no particular order are as follows
$500MR2 (Ed Farrell
Bill Strong (need pics bill)
Grimsby53 (matt)
James Voo (now belongs to Mitchell (meso)
Gandalf (Martin Kloppers) FINISHED!!!! this thing is SICK!!
Starfishman (not completed yet)
Japanese drifter mk1.5 (seen in option video)
Links to swap Information
Paul Woods' Excellent write up of when he performed his swap
http://www.mr2mk1club.com/turbo.html
Carl Crawford's excellent write up when he performed Ed's mk1.5
http://www.board.mr2faq.com/forumdisplay.php?s=&forumid=118 They are sticky'd at the top of the page