When it comes to general durability and longevity the 3800 wins hands down. Both are good motors, but after working on both for many years, I don't see to many LT1'* come in the shop with 300+ miles on the clock with no history of having the heads removed.

The LT1 is no better or worse than the rest of the SBC family, nor any more durable than the 3800. A coolant leak into the heads or block is bad. It doesn't matter what motor you are working with.

The real LT1 killer is the leak at the Water Pump drive shaft, since it tends to wet down the Opti-Spark distributor and kill it. 2nd place goes to the rear intake to block seal, which gives out and the motor starts bleeding oil out the back. 3rd place is the cheap freeze plugs put in at the factory, which are thin and rust through, leading to a coolant leak in difficult to reach places. The basic rotating assembly and block are pretty good stuff. The heads have the usual valve seal problems that all SBC'* seem to share, but are otherwise sound. The head gasket is good, but like any motor with aluminium heads on an iron block, it doesn't take overheating well.

Last, are the actual drivers/owners/mechanics. There are less LT1'* in total and the people who own them trash the livin heck out of them. (or start doing mods, dickin around, etc.) which leads to a higher incidence of failures. Look at it this way..how many 3800'* get the hard use typical of the owners on this list? It'* probably less than 1% of all the 3800'* in service. The LT1 went into cars that, by their nature, are going to get abused a lot more...sports cars, taxi'*, police cars, etc.

There are a whole bunch of LT1s out there that didn't have aluminum heads. All of the B and D-body LT1s are iron heads, and that'* a lot of cars: The Caprice/Impala SS, the Buick Roadmaster, and the Cadillac Fleetwood. I've seen MANY of these cars with 200+k miles that have never had the heads off! And, as mentioned, a lot of them were beat on pretty heavily.

I think the average Joe is a lot more likely to completely kill a 3800 with the intake/gasket issue than an LT1 owner is with any of their respective issues.

I had one. I beat on it. But the 3800 is no less durable.

And that makes sense for these LT1 variants..Iron Heads on an Iron Block. The block and heads expand and contract at the same rate so it doesn't shear the head gasket. The aluminum headed ones can have this problem when overheated. This is pretty much true of any motor with heads of a different material than the block. (Anybody remember the Chevy Vega? )

There were also a lot of mistakes made when working on the LT1 motors...like using the wrong head gasket because the differences weren't made crystal clear. These are part of the learning curve on any new design...even if it'* mostly derrived from the basic SBC design, it'* different enough for people to scratch their heads for a little while and make a few screwups that come back to bite them hundreds (or thousands) of miles later.