I've been contiplating using one of the Holley sniper or fi techs 2 barrel throttle bodies on my inline when it goes back into the car...my question is placement of the sensor in split duals from langdons manifolds...I thought I read somewhere...the front bank runs lean and the last bank runs rich..is one a better choice for the sensor..

With the split exhaust, it might be better to use a two sensor setup like for a V6 or V8 engine. Most aftermarket EFI kits will handle dual inputs if specced properly.

You will get the same results from the front or rear pipe. Hook it to the one that is the easiest.

Even if the mixture matches, the rear cylinder runs hotter than the front, I'd use the rear pipe.

Do they need to be in the header or can they be in the exhaust under the vehicle?