Distributor not going in all the way

[smoothlandin]

83 chevy k20, 350, th400, etc

Original block, smog heads, etc. I just swapped the cam for lunati voodoo, put on edelbrock performer, etc.
In the truck of course, should've pulled it...
I can't get the distributor to drop the last half inch. I know about the oil pump driveshaft, and how they mate, but my problem is that the distributor won't even go in enough to reach the oil pump shaft. I pulled my oil pan, I originally thought the oil pump shaft was the problem, and can see that the oil pump shaft and the distributor are in line with each other, albeit 1/4" away, and the problem must be where the distributor gear and camshaft meet.
I know that the cap will need to turn 20* or so when the teeth mesh together on the cam and dist, but I just can't get them to mesh. My distributor is a factory replacement, with no odd wear, and the cam is brand new.  I've searched, called engine builders, talked to mechanics, etc, nobody has ran into this, and some even came over to help, to no avail.
It has been 2 days trying to get this thing together, in the past I've swapped distributors quickly and painlessly.

[fitz]

  Pull the gear off the dist shaft and see if the distributor drops into place.

[smoothlandin]

Just did what you said b dist drops right in..so maybe I need a different gear?

[bd]

What is the camshaft part number?

[fitz]

Unless its a roller can, your gear should be fine.
You say the dist & oil pump are lined up, but the dist won't drop down all the way.
Most of the time I remover & replace a dist,  its to replace an intake manifold, so the motor is not rotated with the dist removed. A cam swap is a little different.
I'm guessing your gears (cam & dist) are off by a hair. If you turn the dist to line them up, you throw off the dist/oil pump alignment.
Ir's tough to explain, but I set the oil pump shaft so its a little offset from where I want the dist to fall into place.  Now as I rotate the dist to line up with the cam gear, it kinda falls into place, with the dist gear, cam gear, and oil pump all lining up.
It usually takes me a few tries so I can get it so the dist looks "centered" and the aluminum vac port is not aimed at the firewall or carb once I set the timing.

[smoothlandin]

Not a roller cam..I think i know what you mean, as you drop the dist down, it turns a few degrees, changing the correlation of the rotor, and possibly missing the oil pump shaft alignment. Maybe I'm just off by that little bit but I've never had one do this to me.

As far as part number, lunati voodoo 10120702.

[fitz]

Exactly, I'm thinking its just off by a hair.
If you give BD  the part # he can check, but the only time I've heard of people having to change dist gears is when they install a roller cam. Then they have to install a hardened dist gear, but I think it has the same # of teeth on it.
You could also try turning the harmonic balancer a degree or two forwards or backward and see if it helps  the gears line up.
We gotta solve this so you can break in your new cam on a Saturday night.
The neighbors will love it.

[smoothlandin]

Ha, lucky for me I live in the country..I can run open headers all I want, just one neighbor and they're ford guys; so you know, they're constantly working on their trucks
Anyway, I still have the timing chain and whatnot exposed, I have the engine at tdc on #1 ,of course, but have tried turning the motor a little to help ease the gears together, but still no luck. I'm actually wondering if I can install the gear on the disributor 180* from its current position, I can see a little wear on the gear when it's facing the cam with the rotor facing #1, maybe that is causing some of this greif
Closed up shop(backyard) for the night, good t storm coming, but I will be at it in the morning; as long as my wife is cool with that..
Thanks for the help

[fitz]

Your welcome.
One last thought for the night.
If your oil pans still off, you can remove your oil pump. Now you can turn the rotor every which way to see if you can get the gears to line up.

[bd]

There's nothing unique about that camshaft.  It's fully compatible with the factory distributor gear.  When you get back to it in the morning, it will probably almost assemble itself.   

I think Fitz's evaluation is spot on.  So, try a different method.  With cylinder #1 on TDCC, drop the distributor into place so the rotor rotates into the appropriate orientation.  Then have a helper bump-bump-bump-bump the starter over with the key as you gently settle the distributor into position the final 1/2" to 3/8".  The distributor should seat before one complete revolution of the engine by just tapping the starter a little bit at a time.  Then you can crank the engine around and recheck rotor alignment.

If difficulty persists, remove the oil pump completely and stab the distributor.  If there actually is interference between the distributor and cam gears it will be clearly evident with the pump removed.

[smoothlandin]

Well, just pulled the oil pump after a few more hours of trying the suggested methods, but the distributor still won't go in. The gears just don't mesh together.

[bd]

This is a long shot:  Look at the gear pitch of the old camshaft.  Now, remove the distributor and look down the hole at the new cam gear (or look up from underneath).  Do both cam gears have the same pitch angle? 

Contact Lunati Tech Support, (662) 892-1500 (8 AM - 6 PM CST).  Let us know what happens.

[fitz]

You mentioned that your dist gear had some wear on it.
Do you have a spare dist you can try?

[smoothlandin]

The new cam and old cam have the same gear pitch, or close to it, I don't think that's the problem anymore.
But, with the sunlight just right, shining up from under the truck, and a bright flashlight, I think I can see the problem. I didn't even think this could happen.
I'm pretty sure that's either a cam bearing or something in between the cam gear and the end bearing surface. I took some pics, but it's tough to see in there.

[fitz]

Sounds like you will be pulling the motor.