I assume that the LT1 extreme duty and the LT4 timing sets are NOT the same thing.

I was told that the extreme duty is a butt link (non-roller) where the LT4 is a true roller.

Here are some price comparisons:
LT1 extreme duty set 12370835 $225.00

LT4 timing chain 12555887 $50.41
LT4 cam sprocket 12555885 $114.83
LT4 crank sprocket 12555886 $40.06

So which is better for my LE1 cam install?

 

LT1 extreme duty

 

go with an electric waterpump as it along with a true double roller will cost you the same, and maybe just a little bit less. The true double roller is much tougher too. Plus going with an electric wp will keep problems from occuring from the stock wp leaking out the weep hole. onto the opti

 

From thunderracing :

For most daily-driven and mild camshaft applications, we recommend the GM "LT4" Timing Set. For more aggressive engines, we have the GM "Extreme Duty" Timing Set. The Extreme Duty timing set is by far the stronger setup of the two, however, some additional noise may be encountered when going with this item.

 

I want to keep the mechanical water pump to ensure maximum reliability, I am willing to sacrifice the small gain from the electric pump.

So the extreme duty is the strongest but a bit noisier and designed for extreme cams. The LT4 is for slightly milder cams and more quiet plus a tad cheaper.

It appears that the LT4 timing set would be ideal for the LE1 cam.

 

Anyone want to comment on this timing set? It appears to be a roller chain.
http://cgi.ebay.com/ebaymotors/95-96...ayphotohosting

 

You "should" be ok with the LT4 timing set.. but for peace of mind, I personally would do the extreme duty.. only a couple of bucks more....

If your timing chain breaks... you are majorly hosed....

food for thought

 

That set doesn't allow you to keep the water pump drive. Go with the LT4 Extreme duty call Jason Cromer.

 

There is a LT1 chain setup and a LT4 chain setup, then there is the LT1/LT4 Extreme Duty set which is a true roller single row chain kit.

 

I'm running the LT1/LT4 Extreme Duty timing set in my 383, and recommend it. I don't really notice any noise coming from it. The LTx ED is a single roller, but it is massive and strong enough for most setups. It has the advantage of allowing you to retain the gear driven WP... which I agree is a good thing for maximum reliability.

 

Some say the Extreme duty is a true roller and I have read that it is a butt link (non roller).

So which is it from the guys who have it?

 

>I went with the Meziere electric water pump and Cloyes true roller timing set.
I have about 15000 miles and 4 years on both and there are no signs of any problems.

 

The Extreme Duty IS the LT4ED. It fits either the LT1 or the LT4. If ya got an ED it was originally made for an LT4.
Yes it is a roller.Like said above it IS a single roller. According to Cloyes who makes them for GM they are AS strong or stronger than a SBC double roller.
Have not had any trouble with them and running 250/600 spring pressure.

 

As 1racerdude said, the LT1/LT4 Extreme Duty set is a true roller. And he's dead-on about Cloyes making them... for my build-up, I ordered the ED set from GM. When it was taking too long, and holding up the build, my engine builder ended up ordering the same ED set directly from Cloyes.

The ED set is strong, more than enough for most peoples applications.

 

Something that should be mentioned here, for anyone reading this thread: The LT1/LT4 Extreme Duty timing set is only meant for '95+ engines. For '93s and '94s you need to swap in a later-model cam (not usually a problem, since you're probably installing the timing set along with an appropriate aftermarket cam. But you do need to swap to later timing covers and optis in order to use the ED set.