The amount of labor involved in any given operation and the potential for disaster if the part fails dictates the quality of the parts you use.

Is doing a heater core on a 700 series car a nightmare? I've been working on the product for 20+ years and I say YES it qualifies as a nightmare to do.

What is the disaster potential if the part fails? Best case, you get to do the nightmare job all over again. Worst case you BBQ the motor due to coolant loss and the car is potentially a write off.

All that being said I would spend a little bit more money and put in a factory Volvo core, even if it is twice as much as the Four Seasons brand. Please don't think I am bashing the Four Seasons product as I have used some of their stuff in the past and it looks to be well made.

If you are wondering what the odds are on the "worst case senario" really happening then you need to talk to my daughter. She just stepped into a really well kept 1990 16 valve that someone else's daughter ran out of coolant due to a leaking heater core and BBQ'd the head. I got the distinct pleasure of going through the entire top end and putting a heater core in it. I presented my daughter with a bill just so she knows what the old man does for her and what someone in the real world would have to pay. It was in the area of $4000.00! Needless to say I gave the previous owners just what the car was worth, about $100.00.

You pay your money and you take your chances.

Good luck,
Mark