Cameron;

I certainly don't "dislike Bosch stuff"! Bosch equipment, INCLUDING their alternators, is well engineered and manufactured to be well performing and reliable. Everybody knows what electrical manufacturer's products I absolutely despise, and what country they're from...does the term "Prince of Darkness" mean anything to you?

...so I will try to answer your question of what the benefits of using a Delco Alt instead of a Bosch are:

Retrofitablility: Early B18 will not accept a Bosch alt. They do not have the mounting boss which was cast into the later B20 blocks (hell, you might say, they wont fit a Delco alt either!)...right, so if you have your heart set on installing a Bosch, fine...IPD will now oblige you with a bracket, if you want to install a Delco, fine, contact me... this is America, (and do we love it!), so there's always multiple options!...and the agony of the choice is yours, you just want to be aware the final, and long term, bottom line cost...see below.

Availability of Service/Replacements: The very first Delco alt in our group of acquiantances was developed out of necessity. Bob G. who loved, rebuilt, kept his car in fine mechanical shape, and used his Amazon daily needed to make a trip. No problem...but somewhere between home and wherever, his Bosch Genny based charging system failed (on a Sunday night in the middle of nowhere). Without going into details of the story, he vowed then and there, to NEVER have a charging system based on a device which could not be easily serviced, or replaced when on the road ANYWHER/ANYTIME, in the US...and it also seemed to be a great time to install something which had a bit more output scroat!

Reliability: As I stated before...Bosch alternators are without a doubt "The Good Stuff", but so are Delcos, but there will always be people who can tell their own personal horror stories about either brand...I believe its a toss-up in this department...but if you install a 100k mi Bosch out of a tired old 240 with unknown mileage, or a $40 "Rebuilt Special" from Pep Pills Boys, you might remenber that old saying about getting what you payed for, and keep the horror stories to yourself!

Cost: It's an ecomony of numbers thing...Bosch alts are at least twice as expensive as the Delcos, since there were so many of the later manufactured... plus when you walk into a parts house and say "Bosch and Volvo", they don't look at you like a Grizzly eyeballing a juicey king salmon...for a snack(!), after which they tell you they don't stock it, but can order it for you...just leave a deposit and stop back tomorrow afternoon (oh, and: "Special orders are non-returnable)! The bottom line is that its advantageous to use something common as dirt...it typically makes it less expensive to upgrade to a Delco alt initially, AND ALSO come service time down the road.

I hope that answers more questions than it brings up.

References:

For additional technical (and non-technical) info comparing Alts and Gennys see: http://www.intelab.com/swem/gen_alt_diffs.htm

This is not the place for advertising, and I would never use it as such, but in this case, I refer to the link: http://www.intelab.com/swem/altkit.htm because this post is long enough, and I don't feel like restating the addition info I've compiled there.

I'm rolling...sometimes with Bosch, sometimes with Delco...main thing is: I'm rolling in my Volvo oldie!

Cheers