GMC Repair: 1992 chevy Silverado 2wd shortbed, valve stem seals, 350 chev


Question
My truck has the v8 350. It has 212,000 miles. It runs pretty good now. I went for 3 months with a bad idle problem. Between the mechanic i work with and I, we replaced every sensor, the distributor, did a tune up, replaced the positive cable because it had swollen, and finnally replaceing the injectors which ended up being the problem. The passender side injector on the throttle body had shorted. I replaced the transmission at 180k. The only thigs original on the truck(conserning the engine) is the starter and p/s. Do you think the engine will last me another 25-50k without major problems. Oh and the rear diff. has never been worked on either.  

Answer
I believe 350 cid chevys are the strongest motor out there,ive had them last to 500000 miles and with that the only problem that eng had was it finally began leaking oil through the valve stem seals and guides,if you maintain them with proper oil changes,every 3000 miles,and just routine maintinance such as coolant flushing and such they will last for a good long time.
 Your eng i couldnt answer because i dont know how it runs,does it burn oil,is the compression in the cyls good etc,if all is good on the 350 chev then just keep a good maintinance record and it be good for a long time.
 The rear diff,i would change the fluid,also change the fluid every 10000 to 15000 miles,i know im gonna get it from all the techs out there,but let me tell you that rear diff will last twice as long as any other,and use a synthetic diff oil.

ED