I know it is a wee bit of reverse engineering, but it would look wildly cool to have 2 rows of 6 carb throttle bodies on a v12 engine beneath the bonnet of a replica of a '30's something tank style race car. Does the gm tranny in this thing rely on any electronic signals? or could I scrap all the electronics in favor of a simple push button type of solenoid starter with very minimalistic wiring under the hood? Maybe yank a front axle out of a junker 30's - 40's whatever and use the existing jag rear end, cobble together some frame rails and have some modern-nostalgic fun.

 

are these three speed GM transmissions at all controlled by wiring? I know some transmissions are ecm controlled but I figure that this is old enough to not be.

 

Transmission uses a cable shift which seizes with rust when left for long periods
and a semi electronic transducer to run the speedometer.
Nothing there that can't be overcome.

May I suggest you google "XJ-13" and consider building a replica of one of the sexiest Jags never made?

 

How long back does one have to go to get a carb intake for one of these engines? Is it like really old and a lot of money? or like yesterdays junk not worth picking up?

 

The last of the E-type V12s were still on carburettors circa 1974/75. The V12 sedans got fuel injection about the same time...so for the 25 years the Jag used the V12 only the first 4 had carbs.

If you look long enough you could probably find what you need.

Cheers
DD