I'm installing my vented opti, first time, 97 LT1.

I have the factory service manual but am a little worried about getting the timing right.

The manual says,

1. Align distributor driveshaft slot with distributor base timing mark.

2. Rotate the engine crankshaft until number one piston is at top dead center (the intake and exhaust valves closed). The camshaft pin will be at 9 o'clock position.

3. Install the distributor.

I've done a million 'old' smallblock HEI installs, and can do that blindfolded. I figure I could take the cap off the opti and use the same basic principals as a standard HEI but it seems like it should be more straightforward than that on this application.

But it seems that the opti could go 'on' 3 different positions, meaning the dowel in the cam could fit in the opti drive 3 places. One seems like the obvious choice but I want to be sure.

 

Rob from shbox.com was kind enough to share this:

All you have to do is look at this on my website:

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

Visit my site at: http://shbox.com/1/4th_gen_tech1.html


Rob

So I'm not sure why the factory manual goes through all the TDC hoopla, but yeah it seems to make sense that the opti can only be 'right' in one place on the cam.

 

You really can't screw up timing on this car. The opti only goes on one way.

 

Yep - get the slot in the drive and call it a day.

 

The TDC thing is probably to let you get the opti slid by the crank hub. If the hub is on, the engine must at 1 or 6 to let the opti pass by and go straight on.

 

Unfortunately, a large number of people have managed to put the dowel pin in the incorrect hole, usually accompanied by a little bit of extra force in seating the Opti against the block. Can and does happen on a regular basis.