My OctaCapture has 8 analog and 2 digital ins.
Following Roland Marketing department's logic, it should have been called DecaCapture.

Not knowing exactly what's on the individual tracks:
Could it be enough to record the tape as two track stems (=two tracks per one SONAR track)? Would that give you enough flexibility to go on with it?
Or as one two track stem plus one single track, and then one track as a separate recording. If that one separate track would be, say, drums, you could sync it manually to the others.
 

I used a Korg D888 direct from my T-238 and recorded all tracks at once. This is the only way it should be done with analog.
 
If you record each track separately, each time you rewind to play the next track the tape will stretch just enough to go out of sync.
 
Yes you can slip-stretch afterward if you want to spend the time post editing your work but that can get tedious and sound quality will be affected.

I haven't used it and it seems a bit over the top but Celemony, the company that also makes Melodyne, has "Capstan", software specifically designed to fix tape irregularities. It's crazy expensive but they also rent it out per day. Depending on how vital this project is to you it's maybe worth a look. I think it's the only thing on the market that can do what you're asking.

Sanderxpander
I haven't used it and it seems a bit over the top but Celemony, the company that also makes Melodyne, has "Capstan", software specifically designed to fix tape irregularities. It's crazy expensive but they also rent it out per day. Depending on how vital this project is to you it's maybe worth a look. I think it's the only thing on the market that can do what you're asking.

That's actually a very good idea. I've never used Capstan before but the reviews have been great.
There is a demo but im not sure of the saving / usage capability's of the demo. Its definitely worth a shot though.
http://www.celemony.com/cgi-bin/WebObjects/LicenseApp.woa/wa/demoRegistration?item=capstan_demo_win&language=en
 
 
 

If you put a consistent slate mark at the front of each of your four tracks on your analog machine that is to say arm all four channels on the analog machine and click a pair of drumsticks loudly so that that click gets recorded at the front of all four tracks

Of course this is just one recording and recording all four tracks at the same time with just one click or two if you have enough space or 3 if you have enough space whatever

You can then transfer one track at a time or two at a time and then in sonar line up your slate marks

Just make sure that you
are recording each track to an individual track in sonar

I've done it it works

I have an OctaCapture and have used it extensively for transferring my analog 8 tk tapes from my Tascam 58 to Sonar.  It has always worked without hiccups (yea) and, for other projects, have it digitally hooked into my VS 100.
 
 

OP has a Quad Capture. And though I see it recommended by someone to do 1 or 2 passes at a time and try to synch it up, It will never happen. these aren't digital recordings were there is no drift. Analog is unforgiving as no capstan motor is right on the dime every pass through.
 
With each pass there are fluctuations (to make things worse..in different spots) thus making a synch line up merely impossible.
So far the best advise I've seen is using a 4 input digital device or Sanders idea about Capstan (which I haven't explored but sounds promising).