Firstly, I think you're perhaps a bit crazy (aren't we all?)

For one, I really like the simple (and elegant) direct linkage. Why do you want to change it (unless it's not working or not set up right)?

Second, a 'mild B18' and you're running DCOEs? I'd switch back to stock with a *good* set of SUs... keep the Webers on a shelf for when you build an engine that can really make use of them..

That said, I expect you'll have some fabrication if you really do want to cable the throttle. I'm sure you could use some parts from an E or ES (pedal, brackets under the dash, cable). But you'll have some fabrication under hood to adapt from the fuel injection setup to the carbs. Maybe there are options that could be had from Weber parts suppliers...

Seems more trouble than it'd be worth to me.
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-Matt I ♥ my ♂