Stuck here....on a budget for the next year. I've got a 1991 305 with 186000 miles on it. Holds great oil pressure. Smokes at start up (alot).

I can afford to rebuild the 305, but cant afford to install a 350 yet. I need to put another 20-30k miles on this car. Frequent oil changes and regular tune-ups.

What do i need to do to get another year out of this thing? Until I have the cash flow to put in a new 350 with all the goodies plus a new trans.

Should be ok for another year. Mine is close to 400K and still running. I'm about to replace it with one around 90K. Cheaper than rebuilding it.

My 305 had 225,000 plus when I pulled it and it still ran great, other than the mentioned cloud of smoke at startup. It also had a 120 shot of giggle gas on it for about 25,000 of those miles.

My old truck now has 413,000 on the original 350. And get this, it DOESN'T smoke on startup. Now that worries me.

Bottom line: change the oil and take care of them, they will run for a very long time. Your motor will be good for years...

I recommend the Lucas Oil Stabilizer, though. I had a lot of great success with that stuff in our fleet of trucks, and have been using it in my truck for a while now.

You can rebuild a 350 cheaper than rebuilding a 305. You only have to swallow the cost of the core. I wouldn't waste my time with a new 305. Start up smoke sounds like bad valve seals. Get those replaced or you can slowly decrease what life is left in your motor. If everything else is in working order keep it for the time being until your 350 is ready.

I'm closing in on 200,000 miles with my 305 and it doesn't smoke at startup. (198,000 miles). But there is an enexplainable "Squeal" from the front of the engine. We changed the alternator, and I am changing the water pump tomorrow. (I'm pretty sure it's the water pump).

But yea, my 305 is nearing 200,000 and my grandfather's/my '88 Chevy Silverado 1500 is up to at least 260,000 on the original 350. and get this. My grandfather bought the truck knew and noone has ever changed the oil in this truck but him save one time.

So just keep the oil changed and try to stop the smoke and it should last you a year (I would think)

Yeah, but that's just a puppy. Wait until you get some real mileage on it, so you can get a better idea of how long it will last.

If it were one of those "high quality" Hondas or Toyotas, you probably would have changed the engine twice already, or at least the head once.

My car has about 200,000 on the LB9. It was only raced by the previous owner, for two years! It smokes on startup and when you get on it. I'm looking for some sort of oil additive so it can last till I get the new motor in.

Forget it. The valve stem seals have hardened and cracked. Replacing them is fairly easy (easier than putting in a new engine, anyway), and will solve 90% of the problem.

That goes for you, too, Matthew91-Z28.

If you're going to rebuild your 305, just grab a 350 for an extra $50 and rebuild that. Even a stock rebuild will get you more power than the 305 and you can switch over your TPI/TBI and just get bigger injectors and retune your computer.

It's a total of only a few hundred dollars for alot more power.

If only that were true.

Howdy Bay Area!

I agree about not rebuilding a 305.

I'm just recommending a simple gaskets and seals replacement job. That's all that's needed to fix the reported problem.

Oil additives aren't going to do it.

I'm with 57. throw some vlave seals on it to get by and let it eat. It's a small block, if you really feel bad throw a timing chain at it. See you in 30,000 miles.

I'm not putting any more money into this motor, unless it was a cheap additive. I'll live with the smoke for another month!

geez thanks for all the input. I checked into doing a rebuilt 350 but what was prohibitive (budget wise) was the cost of 22lb injectors (cant find cheaper than $35 per injector), and some of the other items totaled together (afpr, chip, etc.) And the 350 was $300 more than the 305 due to mismatched core.

I may just do valve stem seals and call it a day until I have enough scraped together to get a 350 and build it the way i want with cam/heads/intake.

thanks all

I've got a buddy with 230k on an LG4 in a 84 berlinetta. My uncles F150 with the 4.6 trition has about 240k. Take care of it and change the oil, it'll last a lifetime... (well prolly not that long)

Just retired the 305 TPI with 230,000 on the clock. Insides don't look all that bad either!

How will bad valve seal decrease the life of your motor?

Increased oil consumption, decreased spark plug life, carbon buildup in cylinders.

No show stoppers, just annoyances. Changing valve seals is actually a rather simple, if time consuming process, and will eliminate most of your oil consumption problems at startup. I did mine, and now my 190,000 mile 350 does not use ANY oil between changes. Spark plugs look much better, and reduced spark knock on hard acceleration. Parts are less than 30 dollars.