Half day excursion suggestions

Stay in York the full day.

Agree with above. York is worth more than just 4 hours(!). If you just blow in and out in a few hours you will regret it. Spend at least a full day there.

You can consider Blackpool, and see this warts-and-all description by Rick, to which the Blackpool tourist office recently objected. He's going there this summer to learn what's new (but not from those PR folks).

I did think of stopping by Blackpool on our way back from York....

Blackpool is a waste of your time. Spend longer in York, which can easily fill 2 whole days. Harrogate is more worthwhile than Blackpool.

If you want a day trip - consider going to Conway /Conwy and then the short journey to Llandudno. Also visit Chester.

Why base out of Liverpool and Manchester?

Do some research. Liverpool is OK, especially if you like going on a Beatles tour, but pales compared to places like York, Bath, Oxford, the Cotswolds, the Lake District and more.

Manchester!!! get serious.

You need a minimum of two full days in York. We spent three nights there and had about 2 1/2 days to tour and were busy all the time.

Emma, thanks for asking. We have family in Liverpool, hence it being our base. We will be flying in to Manchester from Orlando so why not see the place while we’re there, right? We’re going to be staying 3 days in Liverpool and one of those days I want to go see York. We will be driving there and I just thought that on the way back we could stop by another town. I don’t know if we want to spend all day in York. I guess we’ll see once we get there...
Then we go to London, but that’s for another post 😉

A couple of hours' drive each way to see York, so start early and get back late. You'll have time for the Minster, the medieval center and wall, one of the museums and maybe a second one if you don't linger or take long for lunch. York wouldn't be my idea of a day trip from Liverpool, but it's doable if it's really important to you to be there.

Chester is much closer, very charming and interesting with a fine cathedral, walls you can walk, beautiful half-timbered buildings in the center, and more. Not as much to see as York but a lot easier to reach from Liverpool, a very worthwhile day trip. Conwy is also good, about 1 1/2 hours each way, medieval castle ruins, walls, an Elizabethan house, and other attractions. I'd pick Chester for maximum enjoyment and minimum driving, but your choices depend on your interests.

Edit -- I realized you're looking at a half-day trip, which makes Chester the only logical choice I think.

Just to counter another poster above, I LOVED my time in Liverpool and Manchester (I also took a day trip to Chester from Liverpool). If you want to see how I spent my time, here's my detailed trip report (just skip down past the Glasgow sections): https://community.ricksteves.com/travel-forum/trip-reports/uk-trip-report-glasgow-manchester-liverpool-in-september-2016

Take the train direct from Liverpool to York, rather than driving. It will be quicker and you won’t have the hassle of parking in York.

There is plenty to see in Manchester, although it’s not as twee as say York or Chester.

Thanks for all your suggestions. I will take them all in consideration as nothing is yet set in stone. I really would love to see York though, maybe do a Viking tour.
Also learned a new word - “twee”. Never heard of that before!