what wheel offset has a 1980 escort van

Mk2 sedan with 13x7 6p with 205/60R13s under rear, 13x6 12p with 205/60R13s under front - if that helps any
 

 

+12 offset for a 7" wheel shouldn't touch standard guards (front and rear) on a sedan provided you don't go too wide on the tyre.  Note that this is for an alloy wheel, which is most often 1" wider overall (i.e. measuring the outside width) than the cited (inside) width.  I've never seen a Dragway with the tyre off, so I don't know if the same +1" rule applies.  If it is less (steel rim?), then you have more room to play with.
 
Assuming the +1" thing above though, a common fitment that keeps the speedo accurate is 15x7 +12 using 195/50 tyres.  I know you want to go with 14" tyres (which are probably harder to get) so you'd need 185/60 (maybe a bit narrow for 7" rim IMO) or 195/55 or 205/55 (both only off the ideal by about 1%)  to keep the speedo accurate.  If you go 205/60s they'll be a bit taller, so your speedo will under-read your actual speed by almost 5%.  Wouldn't be a deal breaker for me; just something to be aware of when you are out driving.  Based on a spreadsheet I made to sort out my own wheel issues for a sedan, 225s on a 7" +12 will rub the guards.  To see whether this might apply to yours, you need to measure the distance from the face of the hub to the inside lip of the guard (a plum bob and a rule is sufficient if you measure carefully), mine being 95mm front and rear.  I suspect that there may be differences with the van though, most likely at the rear.  If you post some numbers, I'll run it through my spreadsheet and let you know how it comes out.

90mm is exactly what I expected for the hub face to wheel lip for  7" wide wheel with +12 offset, so I suggest confirming that 12p is what Dragway cites the wheel's offset as (just to be sure).  You've got a few extra mm on the back over my sedan, so theoretically you could just squeeze the 225s in, as the tyre edge would lie 101mm from the hub face.  That wheel/tyre combo would see you with 125mm from hub face to the inside tyre edge, so it appears that you would have sufficient rear clearance.  Wouldn't hurt to re-check your measurements (measure twice, pay once), maybe this time running the plumb bob directly from the inside edge of the wheel lip.  
 
The front is another matter though, where you will have less backspace and probably a little less distance to the inside guard edge.  My tyres were rubbing on the chassis rail on tight turns with an hub face to inside of tyre edge of 128mm.
 
Of course all these figures need to be taken with a pinch of salt because of manufacturing tolerances.
 

A plumb bob is basically a weight on the end of a string.  The string passes through to the center of the "bob", which has a point on the end, thereby ensuring that the end of the string lines up with the end of the weight.  It is a simple device to check whether something is "plumb" or vertical, and they were commonly used in the construction biz. in days of old.
 
The Mk1 may be narrower (I don't know), but what really counts are the measurements in the wheel wells, so it's worth checking and double checking these so you don't make an expensive mistake come purchase time.  I was confident that the calcs for my car were correct, but I still sought out someone who had a similar set up to be sure, which admittedly would be harder for you with your van.
 
 

ok,  i just did what you suggested with the plumb bob plus this time ive put a water level on the axle housing while i jacked the car up (by the axle housing of cause) to make sure the car was plumb, from the hub to the plumb its the same as yours 95mm and the back space is 154-5mm, so i may have to go for a narrower tire, thinking 215's now
 
thank you so much for you info