700r4 trans did have a computer it told the trans when to shift into overdrive, the first 3 gears are mechcanical, if you click on the hughs perfomance link above and it shows the 4 prong plug, and i believe prong D says it from the ECM which tells the trans when to use overdrive................ so you can use a 700r4 with out a computer but if its a lock up converter style the converter wont lock in, unless you rewire it which is what im doing and thats why overdrive dont work.
http://www.hughesperformance.com/pdfs/HP700-R4.pdf