In every 4 cylinder dual carb set up I've worked on, the cable has always been routed a little on the shade tree side; between the engine tin and front tin seal. It works, but I don't like it that way.

Does anyone make a good cable that's long enough to go through the stock hole and reach to the carb linkage?

I ordered one from Terry that was 4" longer. A long time ago... Are they still making cables? If so, they'll make whatever length addition you want.

You can order the fable and/or the sheath any length you prefer.

Yep. And I ordered the longer cable for exactly the same reason you mentioned Perry.

This is also on my to-do list. So is 4" longer than stock the correct length to run a cable through the factory route to carbs? I don't have an old cable to test with to see how far short if falls.

I was testing a new cable that was supposed to be for carbs, but it was stock length and doesn’t fit right. I routed it the way I wanted and took a picture to show the vendor how much longer to make it. I have a CSP linkage, and 4” longer would work perfectly.

4 or 4.5" is what I ordered as best as I can remember. It was 7 or 8 years ago. I am using the CSP linkage.

Being that the engine is further back in 911's and VW bugs, could a cable from one of those be used as they must be longer than a mid engine vehicle?

Depends... If the ends are the same, why not.

So what is the best way to route one for carbs?

Asking for a friend, snort.

Through the grommet on the passenger side of the engine tin

HA - kind of walked into that one....

How about angle and any attachment points before meeting the hex bar?

Thanks gents! I'm also running CSP and have not fabricated a cable bracket yet so sounds like a 4" longer cable will do the trick and I can make up any minor adjustment when I make the bracket.

Yep

Attachment points... You don't want to get all crazy with bends trying to route an accelerator cable to tight and neat. I use whatever is handy that will work. Secret: A couple of zip ties. Be creative but tidy.

I even still have my original canvas loop strap that attached to the ECU bracket for routing the cable http://www.914world.com/bbs2/index.php?showtopic=335732

If anything a /6 cable will be shorter. You would think it would be longer but it doesn't have to go up and over the the engine.
Below pic of my /6 conversion you can see the stock /4 cable is just short of being as long as the speedo cable. I custom made the cable tube to put a S-bend to shorten the run of all 3 of the /4 cables.