I see that the vented Opti is cheaper then the 93-94 sealed one, and I do hear that the vented one is far better. However, everyone is saying they are putting em on their 93-94 LT1 cars. is this true. One type is "splined" and the other type is "doweled". What mods must be done if any to the shaft that the opti goes onto. I do not want to buy a vented opti and push it onto the wrong type of shaft. I have a 94 Z28, and do not see a vented opti working on it, even though i want one on there.. what to do ??????????

 

Get the unvented from Dal at VanDevere ($280), the vented will cost alot and be a ton of work to make adaptable.

-Dustin-

 

(the following is plagerized from a different forum)
Generally the vented is looked on as being better.

However, it's not just a one for one swap. If you're a 93-94 and have a non-vented, you'll need the following for a vented swap:

95+ timing cover
95+ timing set or aftermarket equvilant
Vented Opti
Vented Opti electrical wiring harness (some minor fab to the plug is necessary but not hard)
Vented Opti Vaccuum harness
Lengthened dowel pin on the camshaft to drive the opti.

I want to say that's it, but I could be missing something. The nice thing about the conversion is that you will subsequently have the ability to run an LT4 Extreme Duty or Cloyes true roller timing set.

If you buy all the stuff from Dal, it is just a little more than an unvented opti. When mine fails in my 94, I'm going to do the upgrade to a vented unit.

 

If you want to put a vented Opti on go here :

http://para.noid.org/~muttvette/opti.html

Or you can vent a 94 Opti yourself and buy the Factory vacuum harness which is what I did

 

Dal's prices...
Vented opti= $189
non vented= $289

If you get the vented one, and the parts to convert you spend just a hair more than the non vented price.

 

Good website. It seems I forgot about the cam change. That adds a ton of work to the project... Good time to put in a better cam! LOL

 

I'm not sure what was meant by this post in reference to my last one, but Van Devere's price for me on an unvented was $280+ tax, trust me I know since I live 35 minutes away and picked it up myself. The vented IMO isnt worth the time and difficulty involved. Not to mention the additional cost of necessary parts as listed above. I looked into the vented procedure, but realized to do so was opening a whole new can of worms. Plus I was going to get a new vented for $75 and it still wasnt worth the trouble for me. But I needed my car ASAP, I guess if you have the free time, do the cam too.

-Dustin-

 

you dont NEED a new cam but you do have to pull the cam out to put the longer pin in it so you might as well change it........
before somone tells me it is possible to change the pin in the car... I suppose i coud be done, at the risk of knocking out your cam button and destroying your lifter / bores IF you were able to rent a cam dowel puller....I got 2 cars on the stock un-vented opti one at 79k and the other at 113k. IMO its not worth going to the vented unless you plan on doing a cam / timing chain swap.

 

There's more to the cam diff than the pin length
The vented opti cam nose' are drilled [93-4 stock cams are not drilled, tho most aftermarket cams are]
That's why cam SWAP is needed..

 

not drilled? for a pin? There is a pin already in there, just a shorter one, Or do you mean the center hole, I think I remember somthing different with the center hole but I can think of how that would interfere.

 

The cam face on 92-94s are solid. 95+ had a huge hole in the center for the vented opti. You WILL NEED a new cam.