Is this old steel frame MTB too big based on standover clearance? Background: I'm a road bike rider but I bought a cheap but well kept old chro-moly steel frame 26er mountain  bike (80s or early 90s model Miyata). I am planning on converting this to an ebike with a Bafang mid drive kit.
I can ride the bike fairly comfortably with the seat post most of the way in. No problem with reaching the handlebars. BUT if I'm standing over the bike in my shoes, the top tube is definitely touching my balls and pushing them up. There's no clearance. I know the importance of standover clearance is debated so I'm not sure what to think about this. The bike definitely feels large but I don't know how much this is a function of the frame being an older design with a horizontal top tube, me not being very used to MTBs or it just being too large.
Would you say that the frame is too large for me? I like the frame but I don't want to use it for the build if it's too large. I'm just not familiar with how these old bikes, and old MTBs especially, should feel.
Thank you!

This is intended to be used on road 100% of the time, for commuting up some steep hills.
If the bike is comfortable to ride for you, then it is a good size for you.  While standover room is important, you might choose to lean the bike more when stopping, in order to reach the ground.
One option is to fit some slick 26&quot; tyres to gain some extra tolerance for the bearings  - you'll want to do that anyway.  Something like the &quot;continental Grand Prix 26 inch&quot; is 1+1/8&quot; and has a road biased design.   Compared to a 2&quot; tyre you'll drop the frame about 35-40mm.   Do consider pedal strike on the road though.