Interference can affect any wiring. On my '81 pickup, I routed the TBI harness though the air gap on the Victor style intake - to the front of the engine. The ECU sits on the inner fender panel of the '81. The way I routed it, it really doesn't get near any other wiring. I even routed the sparkplug wiring under the headers against the block. On my '85 TA, the TBI harness runs across the sparkplug wiring on the passenger side of the intake at a 90 degree angle - separated by an inch or so. The harness is in the distributor area, but distanced from the distributor. I don't run any primary harness wiring near or under the distributor - with the exception of the two wires connecting the distributor magnetic pickup assembly. I plan to change this one day as the sparkplug wiring will look a lot neater running under the Victor intake runners and out the sides, and then over the valve covers to the sparkplugs. This will even further distance the TBI harness from the secondary wiring - still away from the distributor and give a neater look there. Of course, all engines don't have rear mounted distributors. But for those that do, the harness should route forward or across the side of the engine. You already know how your OEM Camaro harness was affected by your distributor - and how difficult it was to find. Any primary wiring near a distributor or an ignition box/box wiring is bad news. Short answer - I don't route any ECU harness wiring against, under, above, or around the distributor. I keep it all as far as possible away from the distributor. My MSD plug wires are 40 Ohm per inch spiral wound, but I still prefer all harness wiring as far as possible from any secondary wiring.