I keep hearing so many differing stories regarding this and most late third gen smallblocks, that they are cheap trash that you are lucky to get 100k miles out of.
And then I hear how these engines are absolutely wonderfull and will run forever if not tortured and properly taken care of.

So I figured I would pose the question here, what should I really expect from my engine? I've been under the latter impression myself.

 

well i'm sure there are others out there that got more miles out of theirs, but i had 131k on mine and rebuilt by choice - not force. my valve seals were bad so that was one thing i wanted to fix, then got talked in to the new cam, etc. anyhow, other than some "unknown" findings when i ended up tearing all the way down, my engine was running great, and even still had some cross-hatch in the cylinders. and that's with living on pennzoil, too. i'd swear by mine any day of the week and it didn't wear pre-maturely... just my $.02.

KAM

some of what i found, btw, was damage caused by gm when they pulled my intake one time under warranty... i found one of those intake gasket grommets in the oil pump screen and gasket fragments that over time, got in to the oil system and pretty much ruined the bearings...

 

The L98s were very well put together engines, and just like almost every SBC, if you take care of them they'll take care of you.

 

Yes, their worst downfall was a two bolt main block but that is perfectly satisfactory for an engine that can't hit 5000 rpm anyway.

 

Neglect and improper maintenance will kill a motor faster than anything. As long as you take car of it and maintenance it regularly you won't have any problems. I can't believe how many 200+k mileage TBI and TPI cars are out there. TBI motors seem to last a tad longer on the basis that they have less parts and have more durable injectors than TPI. I know there are a few dozen 350 TBI guys on this site with 400k

 

SBC are made really good.... c'mon the have been making'em for like 50 years...sometimes it just depends if the engine was neglected or not

 

When I pulled that lil 305 the bearings looked like they had barly been run in. And it had 90,000 miles on it. Take care of it and you will be fine.

 

YEah, my friend has a 1989 Camaro RS with a 305TBI, it has over 500k on it

 

My 91 L98 has 171,000 miles on it, and it'll be coming out next week. Not because there is anything wrong with it, but for a more powerful engine. It still runs awesome, besides the valve guide seals

 

My 91 L98 has 171,000 miles on it, and it'll be coming out next week. Not because there is anything wrong with it, but for a more powerful engine. It still runs awesome, besides the valve guide seals

 

1991 305 with 185k mi. Having bad valve seals is the only internal problem that has developed (knock on wood).

But I have had 2 tranny rebuilds.

 

My shortblock has 170,000 miles and runs GREAT. Heads and valvetrain was redone during the cam swap, but it ran great before anywork was done, (other than the obvious maintenance).

The valve seals have always been an issue, but that's not a huge problem. I'd hardly say that makes 'em "bad" motors. Smallblock Chevy's will run FOREVER if ya take care of 'em.