The /e/ vowel is spelled <e>, or <ea> in bread. The vowel /u/ is usually spelled with <oo>, with alternatives <uCe> in June, <ew> in slewed, <ou> in wound and <ui> in fruit and juice.
The contrast is between a short and a long vowel and the sounds are a long way apart in the mouth, so this is not a problem for learners.
The only pair involving a taboo word is ken/coon.Interesting pairs include:
Betty booty
jelly Julie
Jessie juicy
lemming looming
The mean density is 1.7%. The pairs make 80 semantic contrasts, giving a loading of 60%.
bed booed bell buhl bell boules ben boon bens boons best boost bested boosted besting boosting bests boosts bet boot bets boots betted booted betting booting Betty booty bled blued bread brewed Des do's Fed food fell fool felled fooled felling fooling fells fools fettle footle fleck fluke flecks flukes phlegm flume fret fruit fretful fruitful fretfully fruitfully frets fruits fretted fruited fretting fruiting gel joule gels joules gen June gens Junes guess goose head who'd hell who'll hem whom hep hoop jelly Julie Jess juice Jessie juicy jet jute ken coon kens coons kept cooped leapt looped lemming looming Len loon Lenny loony lens loons Les loos Les lose less loose lessen loosen lessened loosened lessening loosening lessens loosens lesser looser lest loosed let loot lets loots letting looting let's loots letter looter letters looters many moony Med mood men moon mend mooned mess moose messes mooses Met moot ness noose nesses nooses nest noosed pedal poodle pedals poodles pep poop peps poops read rood read rude red rood reds roods red rude redder ruder reddest rudest ready Rudy ref roof reft roofed Rennes rune rest roost rested roosted resting roosting rests roosts retell retool retelling retooling retells retools Sept souped shed shooed shred shrewd skep scoop skeps scoops sled slewed speck spook specks spooks spell spool spelling spooling spelled spooled spells spools spend spooned step stoop stepped stooped stepping stooping steps stoops steppes stoops swept swooped tell tool telling tooling tells tools tress truce tresses truces wed wooed wend wound wended wounded wending wounding wends wounds wren rune wrens runes yell you'll yes use yeses uses