Sorry you didn't have a reply here for several days.
The question you asked is far larger than the information you provided - unless it's all in the link, which I didn't look at.

First off, $2500 CDN seems kinda steep from my view. But values vary with locality.

On a car of this age, inspection ...

OK

Unplug and re-plug the AMM only with ignition off.
If it runs better with AMM unplugged then AMM is bad as wojeepster wrote.

Other things to check

25A blade fuse in white holder behind battery, on fender wall. Keep holder in place while pulling fuse or the whole thing will come up off the ...

I've done it three times, changing it via the radiator cooling line. The upper line is the one to use, that's the return line.

I agree on leaving the screen/filter alone. A bit of a pain to get it out, and almost nothing to be gained by it. I hear there's a Volvo service bulletin saying to leave it ...

....The local junkyard has a few 740's with electric fans. Is there any value in converting my 89 240?...dave

Yes there's value in converting (I did).
But I can't promise that a 740 fan is the thing to use.

From what I've seen the fans in 740s are small pushers, little fans in front of the rad ...

my 91' 740 will not go into overdrive until at least 10 miles go by. then i have to pull over and go through gears. I replaced overdrive relay to no avail. anyone know about this?...thanks
Ed

I suspect the tranny fluid as suggested by billofdurham. It seems like something has to get thoroughly ...

Here in the US the last year for 240s was '93.
740s ended in 92.
940s with non-turbo 4-cyl went through '93 I think, and the turbo 4-cyl ran through '94 or '95.

For our next car - whenever that will be - I'm thinking a late 240 or a 940 turbo 4-cyl. I've heard very little good and plenty bad about ...

Greetings, ...
second question; one of my two belts is missing. It was there last week. The other belt seems pretty tight but I know they put two on for a reason, could it slip that much with just one belt to cause the car to die?...

Definitely use two belts. Get them in matched pairs from an ...