I just purchased a 1976 265DL wagon over this past weekend. I spent several weeks researching the V6 engine and reading many negative reviews of it, as well as a few positive reviews, mostly stating that with proper maintenance the engine should serve you well. But not being one to run from a new adventure, I purchased the 1976 265 wagon anyways.
I must say the engine is very interesting. I just spent over an hour just checking the cap and rotor and trying to replace it. PRV placed the distributor directly under the fuel distributor for the fuel injection system and it is a pain in the butt just to take the cap off and on. I changed the plugs on the passengers side, but will have to remove the air intake box to get to the drivers side plugs. PRV did not put any thought into general maintenance on this engine.
As far as the way it runs, I actually was very impressed driving it home 75 mph on the expressway. It seemed to have a fair amount of power and ran smooth, but the gas mpg really was poor. I could almost see the gauge dropping with every mile I drove. Anyways, if you are thinking of buying a Volvo with a V6 engine in it, if you don't mind taking a little extra time to do general maintenance, I would not let the engine stop me from buying the car.
Tomorrow I'm going to change the engine oil and filter and also install a new trans filter as well as install the drivers side plugs, so if my opinion changes after these repairs, I will let you know, but so far, I'm happy with the engine, but get surprised with every new repair, I undertake.
If anyone has any suggestions on what else needs to be done to keep this engine running good, please post.