l98tpi

My LT4 bottom end came apart and toasted the crank. So have been looking for a used engine and have found one to purchase. It is an LT1 from an 95. It has just been rebuilt and heads reconditioned. My questions are;

a) Is the bottom end, short block, the same?

b) Are the heads the same except for the roller rockers? I would like to just use the heads already on the engine and put the roller rockers on.

If there is anything else I should know please let me know.

Thanks L98TPI

Sidney004

The bottom end is the same. The LT4 has better heads but you would need to swap out the LT4 intake manifold as well. If you don't want to swap heads, the roller rockers will bolt on.

l98tpi

So the heads and manifolds are not interchangeable? If not I will use my LT4 heads and manifold.

James93LT1

http://www.grandsportregistry.com/lt1vslt4.htm

l98tpi

thanks. Answered my question. I guess we will swap heads. I am probably going to go with the LT4 hot cam or similar too.

93 ragtop

Quote:

Originally Posted by Sidney004

If you don't want to swap heads, the roller rockers will bolt on.

Not true. The factory roller rockers are a metric thread. You would need to at least change the studs as well.

Sidney004

Thanks for correcting that, I bought aftermarket Crane Roller Rockers for my LT1.

Kevova

Grand Sport Registry lists several differences between LT4 & LT1 including Pistons, Timing set, Balancer ... etc... you could run the LT1 until you can repair LT4. You would need to watch not to over rev LT1.

mtwoolford

Devil is in the details; LT1 had to have EGR; LT4 did not use EGR

93 ragtop

One other question. What is the LT1 out of? If its anything besides a vette, ie. Camaro or Impala, it is a 2 bolt main, vs vettes having a 4 bolt main. Also, if its an impala, its cast iron heads.

Dr. Evil

Also make sure its not a 4.3 Liter v8 out of a caprice.
That said, there are a lot of differences on the top AND bottom end. Crank, pistons, rings, etc. Sounds like you have most of it covered though.

l98tpi

The LT1 is out of a 95 Firebird. I purchased it today and got some additional history from the owner. Short version, he purchased it from a friend who had spun a rod bearing. His plan was to rebuild it, which he did. He had it rebuilt and heads reconditioned by a performance shop which I do know of and they are reputable. After he had it rebuilt, he was working on a street rod to put the engine in. He lost interest before completing the street rod so is selling it. There were some other items such as the ECM, alt, wp.

I am going to take down to the short block and put the Heads,Cam, Intake, injectors, and etc from my LT4 onto the short block. I am going to add a road race oil pan and ATI Super Damper as well.

If anyone needs the heads and injectors and intake from the LT1, I will sale them at a good price. The heads were recon'd at time of rebuilt.

93Rubie

Spayed 4 bolt caps on the 2 bolt LT1's are actually stronger than the 4 bolt LT1's in Corvettes. You should have no issues with the 2 bolt mains. F-Body guys run them hard all the time and they live most of the time.

Kevova

I would be willing to take that old broken LT4 to the dump for you and save you the trouble of taking the freshly rebuilt LT1 apart .....lol.....just offering

BrianCunningham

Don't forget the timing cover and the extra sensor it holds

PLRX

The 95 has different valve covers



I have both (95 LT1, and LT4). If you read the above mentioned link, you will see both are completely different. I remember the LT4 rods were stamped "LT4". The balancer are 100% different. I'd say the block is the same on cast iron. There are many other variations like the PCV lines, and no EGR on a 96. On the EGR is an easy fix, remove the plate, and bolt the 95 EGR on it.

Sidney004

This is a very informative thread; as I've got a trashed LT1 myself and am looking at the options available. If you've got an LT1 Camaro short block and LT4 heads and an LT4 Intake manifold; exactly what other parts would you need to make that combo work? No need to discuss the cam. Thanks!

l98tpi

What is the extra sensor? Is it a crank sensor? Does the 96 LT1/LT4 the first year of the crank sensor?

BrianCunningham

Yes and yes

Part of OBDII requirements

l98tpi

I hope the 95 LT1 crank will work. Anyone know? If not I wonder if I can make it work or can we disable crank sensor input from the ecm? Need some big help with this one.