350 question

[mustangkiller]

yeah i heard from a friend that with the 350 engine, in lets say a 1994 z28. At high miles ~125000 i may have to replace major engine components. is this true it sounds like it could be but i dont know. its not a problem if i had to replace the pistons and cam and what not.

[N20LT4Bird]

Some small block chevys go for 250,000 some go for 25,000 without major work. It all depends on many different variables.

[Joe K. 99 Zeee!!]

Only thing I can think of is the waterpump. Would that meet your definition of a major engine component? Only other thing may be the optispark (distributor). LT-1 engine itself is pretty durable.

[mustangkiller]

thanx guys hopefully it lasts a long time but if something goes ill upgrade and make it faster. FYI thinkin bout buying a 94 z28 and its got 90000 miles on it so im worried bout it dieing so im doin my research. so any info can help thanx.

[markd79ta]

I think your friend is a little confused. The reversed cooled LT1 is an extremely durable engine. Now, that being said, the disclaimer always rests with one, how it was put together, and two, how it was driven. For instance, I have a Buick Roadmaster with the LT1 (cast iron head version) with 143,000 miles. The motor runs like new...it has never had any work done to it except plugs. It still has the original opti, coil, water pump, and even wires. It never developed the notorious intake leak either. In the next month or two, I am going to replace the water pump just for peace of mind.

I replaced the opti and water pump on my '97 Trans AM at 90,000 miles for peace of mind. My weep hole was leaking ever so slightly, and the opti got soaked with coolant when I blew a faulty aftermarket thermostat gasket so I decided it was time. A technician friend of mine, who spent several years at a Chevy dealership, witnessed many Caprice 9C1s converted to taxis with a bazillion miles on them.

Anyhow, I don't think durability is an issue, although, depending on how it was driven, it may have some wear. I am going to have my heads done on the T/A fairly soon...seats, guides, springs, porting...the usual I think it would be good to have the valve springs replaced at some point after 100,000 miles especially if the car spent a lot of its life near the 6,000rpm range. Other then typical head wear, the opti, the pain in the butt plugs and wires, it is very good motor.

Curious, is this friend a F.O.R.D. guy because I would love to talk to him about 351 and typical F.O.R.D. longevity. Chevy 350s tend to slowly fade into the sunset but run forever while F.O.R.D.s tend to break up around 120,000-150,000 miles. The last 351 I worked on, was out of an '84 Bronco. It ran, but the mains were shot, and chunks of the pistons were breaking off, and resting nicely in the oil pan. It had about 140,000 miles on it.

[Miller_Time]

LT1 Longevity

In my experience the LT1 itself is pretty durable- at least the internals anyway. One thing though- if it's an auto check the trans out really good- if it's been run hard you can expect it to puke before you hit 120000. Ive used my 95 T/A as a daily driver for a while now, she's got 140000 on her, still hauls, but has blown through an opti, a trans, and a posi unit over the 30,000 that i've owned it.

[ninetythreez]

..

I drove the pi$$ out of a 93 Z28 for 6 years. I sold it with 237,000 miles on it. Never went into the engine for parts replacement. It was smoking a little bit when I sold it but still had 248 HP after extreme driving on the interstate and a few trips to the dragstrip with only a K&N CAI and a MSD 6A mods. (remember 237/000 miles!!) The tranny had been rebuilt at 150,000 is all the major stuff I did. Just keep the oil/fluids changed and they will last a long time! I recently bought ANOTHER 93Z28 if that tells you anything!!!!!!!!! My 4th Z28 total. So you can see where my heart is on reliability!!