OK, I have a question. What is the true mechanical difference between a 1984 L69 HO vs LG4??

The reason is I have an L69 with a bad engine. I have a possible deal on an LG4. I don't want to loose performance (I want to keep my Z28 with the mechanics at stock spec)....

I've heard rumors that the difference is in any combination from a cam, pistons, heads, and a couple others.

Does anyone know the truth behind it?

Thanks!

 

there are actually alot of differences...ill point out the main ones...

l69 has 9.5 to 1 Compression ratio,lg4 had like 8.5 to 1

l69 has a bigger cam,and flat top pistons,the heads are the same 416 castings LG4's had,the exhaust is another big difference,the manifolds have bigger ports,and the y pipe is a ALOT bigger compared to a LG4

 

You might consider a search, the topic has discussed at length.

JamesC

 

The L69 has...

- higher compression (9.5 vs 8.5)
- better exhaust system
- bigger camshaft
- aluminum intake
- more aggressive carb/ignition settings
- electric fan ('83 anyway...)
- dual snorkel air cleaner (LG4 has 1 small snorkel)
- much stronger "X" connecting rods

Most of this stuff you could take off your L69 when it comes out and drop onto the LG4. It would make an imporvement over a stock LG4.

 

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I'm looking at possibly getting my hands on an '84 LG4 (I currently have an '84 L69).

From what it sounds like you guys are saying, I could transform an LG4 into 90% of a L69 with relative ease (if I'm following correctly).

 

If I were you, while both engines are out, I would move all the L69 parts except pistons and rods to the LG4... i doubt it would be hard to reuse the cam and lifters, as long as you can remember which lifter was on which cam lobe.

 

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