I'm toying with the idea of putting a vented Opti on my '94 LT1, even though it came with a new non-vented unit, since I really want to not have to worry about it dying on me. It's glitched on me a few times, possibly because of the connector (pushing on it with a screwdriver to reseat it seems to make the problem go away for a while); mostly I REALLY don't like having my engine's only timing reference in between the block and the water pump with no way of cooling its internals. What do I have to change to put a vented Opti on my motor?

 

i dont know but i know where you can find the answer...

CamaroZ28.Com Message Board

and if you're going to go through all the trouble, look into aftermarket optisparks from like MSD and ACCEL, that site has info on that stuff too

 

Optispark Swap Page

 

When I replaced the optispark in my old 94 T/A, the cap I bought from ac delco was an updated vented version.

 

Eeek...different cam, timing set, and timing cover? Seems like I'd be better off adding vents to my current Opti. Urbanhunter, did you buy a whole new distributor, or just a new cap? Maybe there is some kind of venting provision on mine that I missed, if replacement ones are coming with that. If you just got the cap, maybe it's possible to use a vented cap with non-vented guts and base?

EDIT: Just looked at the MSD unit, p/n 8381. I never realized MSD made one for the 93-94 motors; looks like this is the answer. Probably $500 well spent, now I just have to wait for my next paycheck...

 

Best thing is to go ahead and do the swap to the '95 opti. 1. you get rid of that splined opti that can be put on wrong and replaced with a pinned unit that can only go on one way. 2. The '95 was the biggest stock cam for the F-body LT1's and you can pick up a few hp doing this.

The MSD unit for the '93-94 model motors are still non-vented units.

 

MSD's manual for the 93-94 replacement (http://www.msdignition.com/pdf/8381_frm27275.pdf) says that it has a vent, and comes with a vacuum harness, which it has pictures of being installed. Maybe it was listed as fitting originally non-vented applications?

How is it possible to put the spline on wrong? I seem to remember that it was keyed to prevent that...

 

It may be keyed, but trust me, it's been done before.

 

'94 B and D bodys got late style vented opti's as well, and yes, the earily style CAN be put on wrong

 

How do you get it on wrong--shove the spline into the cam sprocket/distributor without lining up the missing groove on the shaft with the missing tooth on the sprocket and distributor?

Hawk, that's correct, I noticed that the MSD p/n 8381, the early style optispark replacement, fits on 92-94 corvettes, 93-94 F bodies, and 92-94 full size pickups, whereas their p/n 83811, the late style optispark replacement, fits on 95-96 corvettes, 95-97 F bodies, and 94-96 B/D bodies.

 

I believe the earily opti has many splined on teh shast like the water pump does. It does not have the single keyway like the late opti. That's my understanding anyway. I could be wrong.