I have records that are less than half an hour long, most of them are from the early 1960s. Ironically I have EP’s that are 25 minutes long too and records from the 1970s that are nearly 70 minutes long, most rare 35-50 minutes per single album. I had the long album explained to me by someone familiar with mixing records and how you lost bottom end and top end to accommodate it. I’ve no reason to suspect that it's not true, except that The Best of Budgie is an hour long and nice and heavy and doesn’t seem to suffer from this condition.
The longest album I have may be the longest ever - Todd Rundgren ‘Initiation’ which is over 68 minutes. Wiki says Rundgren had to limit and EQ the master so the bass response was rolled off to keep the grooves small enough to cut onto a single disc; he also had to speed up the first half of Side One (Real Man-Eastern Intrigue) and speed up the entirety of Side Two to eliminate 2-3 minutes from each side. And you can tell. The second side has to be cranked right up and have bass poured all over it. So at some point, between an hour and 68 minutes it all gets a bit messy. Albums that are 50-60 minutes don’t seem affected. In fact I don’t know why bands didn’t always routinely make an album over 50 minutes because there seems to be no realistic drop-off in quality.
Similarly most singles are between 2 and 5 minutes. The longest I have is Bruce Springsteen's 'Incident on 57th Street’ at 10:03, but 7 minutes is quite common and not only confined to Hey Jude. The best long single I have is Man’s ‘Bananas’ which is live and about 15 minutes across two sides.
I don’t know which is the very longest album and single, but they must be around 70 minutes and ten minutes (one side).