Squirters are 93 up, apparently a few 92's may have them but that seems very rare. They are definitely not in 90-91.
GLE in the early 90's 7 cars I believe means 16V/twin cam, and unless you want to make 300hp and up, way up, that may not be the best motor for you. EG, if a timing belt breaks you lose the motor. Get a turbo, simpler, cheaper, more pep.
91-2 had issues with the speedo, some have been able to fix it, some not. There is a simple problem and a not simple one. I have one of each, and one of each problem. Good cars though.
There are some similarities between 2 and 7, but there are many differences. The procedures remain similar though. The 7/9 cars are more refined, more roomy, and some consider them the best car Volvo ever made.