Hi, I am new and joined to see if anyone had ever swapped a 289-302 into a 90 Bronco 11 with V6-5 speed manual. Is it worth the effort and expense? Trans/clutch has just had $1000 rebuild and I would prefer to keep. What problems will I encounter with motor mounts, wiring, etc?  

Have you considered simply installing deeper axle ratios in drive axles??? This would give you a lot more usable power with current engine and reduce strain on clutch too. Also, if you go with a V8 you really need a bigger clutch and tranny too so since you just had them rebuilt, the best route here is a regearing drive axles. Depending on tire size you have, some 4.56 or 4.88 gears would wake it up and make it feel like it had a engine transplant and greatly reduce clutch loading and give you a better crawl ratio too which would reduce the minimum speed that you could travel at without slipping the clutch.  

I have plenty of power. V6 has some oil leaks and I wanted V8 primarily for sound. Bronco is driven on road quite a bit but occasionally goes off road. I have never used it for hard off road stuff.  

Well for what it is worth, for the "sound" you will add a lot of weight to front end which will effect handling, stability at speed and suspension life and if you do not upgrade tranny and clutch it will have a shorter life too. Also given todays fuel prices a bigger engine is not always the wisest choice as MPG will suffer. But, it is your nickle here so you need to be happy.