ok so im ordering a msd opti off summit racing and dont know which one i need for my 94 camaro z28

this one

http://www.summitracing.com/parts/MSD-8381/



or this one

http://www.summitracing.com/parts/MSD-83811/





also should i order anything else while im at it?

also i have a the little blue elbow in my inlet tube but theres nothing going to it and its taped off

 

None, don't buy one as it's a POS. Do a search.

Rich

 

True story.

 

pos????why

 

See bold, over-sized letters.

 

i dont understand...why would you waste my time making a useless post when in the same time you could answer my question...i did many searches and all were usless....idk what one i need...i have the little blue air inlet elbow on my intake but its taped off and there no hoses leading to it....sooo im stumped as to why this is

 

Rich already told you - they're pieces of ****. I'll tell you the same thing. They're pieces of ****. They are either hit or miss. Stock AC Delco optisparks are far more reliable.

Don't know why you'd have the blue elbow, unless it's been converted to a vented optispark. Your car came with an unvented. Does the opti you have now have vacuum fittings/lines on it?

 

I put a MSD distributor on my 94 z28 about 1 1/2 years ago and it's worked great. It seals a 100 times better and converts it to a vented design. I have drove threw puddles of water with the stock distributor and the car has died several times ruining two distributors. I took them apart and they were rusty. We had a bad flood last year and on my way home from work on the xpress-way. I hit several puddles that I couldn't see because it was raining so hard that were way worst than before. I kept thinking this is it. It never even miss fired once. I dont see how so many people can knock the MSD distributor when they have never tried it their self. I notice a lot of people on her like to jump on the band wagon of what everybody else likes. From my experience I would highly recommend it.

 

sounds good....im going to give them a shot as i have always had good performance out of msd...my only question is even if my stock opti has been converted to a vented one can i still buy the one made for a non vented opti car and just replace the parts with msd ones or is there a different spline?

 

if u have a non vented front cover u need the one with the splined shaft which is the 8381. i had that setup on the motor i took out. it worked fine for 7 months and i sold it to a bud for cheap. i have the vented front cover on the new motor and the cam and cam sprocket that works with it. have a gm opti on it now and a new msd i picked up for a good price as a spare.

 

You can tell which Opti you have by:

-vented has 2 vent nipples, unvented does not

From Shoebox:



-timing covers are different



If you had taken the time to "Search" correctly, you would have found:

-the rotor screws are likely to fall out, unless you Loc-Tite them (ditto with OEM part)

-the "timing adjustment" screw has no "0" mark, and is not set consistantly to any fixed position. There is no way to know if you have the timing set to "0" adjustment.

-the rotors sometimes rub on the dividing cover, putting red dust in the unit.

-there have been numerous other problems, that seem to have been "fixed" over the many years this unit has been on the market.

I personally wouldn't pay almost twice as much for a unit that is no more reliable than the OEM part. MSD makes some great stuff.... but they also make some duds. The LT1 coil is an example of a part that seems to fail more frequently than the OEM part. The fact that they make great dual magnetos for NHRA Top Fuel Hemi engines does not mean every part they make is perfect.

But its your choice and your $$$$$$$.........

 

ok so regardless of brand i buy... i think i might have the vented one now....but how is this possible since its a 94?

 

Depends on the production date.... Its a split year....


I stand corrected...

 

Not as far as the opti is concerned. 93-94s were not vented.

 

In spite of what it says on the small photo I posted, from the "Rebuilding the LT1" article, 94 is not a "split" year - at least not for the F-Body LT1. All F-Body 94's had the unvented Opti. The change was made in 95. My 94 is one of the last 94's made, and it had the unvented Opti.

If your engine has a vented Opti, either someone made the conversion (I have converted my 94 to vented), or the entire engine has been swapped. Check the partial VIN stamped on the block to see what year the engine is. Again, courtesy of Shoebox:

http://shbox.com/1/block_vin.jpg