Mounting of a tonearm.


I have an Oracle turntable with a rare Micro Seiki TA-1 tonearm. I don't have any dimensions or instructions for the installation of the tonearm.
How critical is the measurement from the spindle to the tonearm.?
How would i be able to determine the correct measurement ?

The tonearm sounds great the way it is installed but on some recordings i hear a little distortion on the last track and i am wondering if this dimension would have anything to do with it.
Thanks
Todd
tshulba
Thanks everyone for your feedback. I have found after very careful checking of adjustments that the distortion i am hearing is on the record i am playing. It only happens on the last track of one lp. When i first heard the distortion i thought it was in the setup so i tried re-adjusting everything i could but could not reduce it. I was concentrating on that one lp only cause the lp was only 3 weeks old with maybe 5 plays and thought it should not have any distortion it is new. I noticed the distortion from day one but thought it was setup issues. I played a dozen records or so last night and heard some distortion but only a couple times on some 35 year old records.
I am new to vinyl so i am not sure what distortion is part of the setup or on the lp.

I am using a ZYX airy 3 which should track just about anything . I have some cartridge alignment tools on the way , so far i am just using a paper template i downloaded off the internet from Enjoy the music.

Thanks again
Todd
That's good news.

IGD is a function of tracking angle error and the shorter modulations of inner grooves, but that's not your problem or you'd have it on many records. IGD has nothing to do with the age or condition of any particular record, so the term doesn't apply here.

Out of curiosity, which LP is this and what does the distortion sound like? It might be interestng to figure out what's actually happening.
Thanks Doug for providing a good insight to IGD. IMO, IGD is most likely caused by a worn stylus.
Tshulba,

welcome to the whacky, insane world of vinyl! Sounds like you've discovered my number 1 rule of thumb. First assume the simplest (dumbest in my case) scenario and work your way up.
Sorry guys for not replying sooner , have been away.
I have 2 new Clear Audio records that do it. One is Friends of Carlotta on the track Time
After Time , at the very beginning the piano has some smearing type distortion. The second record is Bella- tracks of the heart. The electric guitar has the same type of distortion .Both of the instruments have large amounts of echo mixed in so it could be in the recording. The funny thing is the voices are crystal clear with no distortion ,it is only these 2 instruments on 2 tracks.
I don't know how to describe the distortion i am hearing i don't know the correct terminology for all the distortions.

I have been using Doug's cleaning method with the Magic eraser after every play and the stylus is very clean now. I am now using Audio Intelligent #6 cleaning solution and things are sounding great except for the distortion. I am beginning to suspect the tonearm but the interesting thing is it only distorts on specific tracks on certain records at different locations on the records too.
I have learned alot in the last month and the sound has improved an incredible amount thanks to Doug and everyone else that has helped out.
Todd