Here it is guys a great post from a fellow car enthusist web site .
I used it on my Hot Rod and it worked great.
Just make sure you replace both the seals and it is the best time to replace the wires and water pump.
Follow seal lube or not lube instructions and be careful putting the OPTI on , you will know when it goes in correctly .
I saved enough dough to buy a new Stereo system !

http://www.impalasuperstore.com/nais...mp;whichpage=1

Oh yeah I have an aftermarket Balancer so I had room to pull Opti without taking mine loose or removing it so you would want to check out how much trouble that operation will be.
I read some engines have to be unbolted and jacked up but My 95 had a hole that you could run a inside puller through that is not visable from above or below.

 

good link.

But now since I saw it, well, maybe I still won't need it.[&:]

 

Opti Spark is not the ogre it's made out to be but research into extending their life by simple common sense things such as converting to the late model opti with the vacuum hoses when you get overhauled or a new cam on a 94 and earlier LT1 .

And putting in a new water pump with the weep hole drilled out and threaded with a hose attached that directs any weepage down past the Opti.

The Opti from the factory will give good dependable service for 250,000 miles with a vast improvement in spark technology over HEI or points.
No I don't know why GM did not take care of the weep hole issuebut of course it was a changeover engine with LS on the horizon.
To clear up a little confusion about the vacuum hoses their principle assignment is to suc out the gasses generated by the spark process of which ozone in small amounts is one of them.
By sucking out the ozone and not allowing it to build up it increases the life of the parts that could be corroded by the obnoxious gas.
Moisture is a far secondary problem to the ozone buildup.
It is a good system and very precise so don't bad mouth it for outsidereasons it can't correct and GM did not see fit to correct.