An observed issue with many wire sets is that they can consolidate applications under one part number of wires. Which can result in some being a bit longer than normal, in some cases. So seeking to make some work where they were not really designed to fir from the factory. Somewhere in the STD Ignition Catalog are illustrations of each wireset with their individual specs on wire lengths.
A few years earlier, in the Fuselage years and prior C-body cars. #7 and #8 snaked over the valve covers and had straight ends on them to keep them away from the exhaust manifolds back there. By '72, they had gone to a 135 degree boot for the back, as others had used 90 degree boots with those wires coming in from behind the motor rather than otherwise.
No B-body used the 100A alternator, which has the '66-era high mount rather than the lower mount of the normal alternator on your year engine. Although they did have the larger-amp alternators on police vehicles. FWIW
With the lh exhaust manifold you have, which is not that different than some of the B-bpdy manifolds, #7 would have to be a 90 degree end.
Wire routings back then were more about assembly convenience that now. Provided the wires need to cross to prevent induction-crossfiring at some point in their paths. Not necessarily whatr we might like if we were doing it ourselves.
Possibly there is an online illustration of exhaust manifolds for RB/B engines which might equate to your casting number and such, so that other applications might be determined. With the end result of ordering a wireset for that application? Otherwise, if all of the other wire lengths fit, you can gently slide the existing plug boots up on the wire, remove the crimped-on terminals then replace the straight boots with what you need to fix the replacement?
One reason that some Chrysler Corp engines have the wires as they do is that at the assy plant, the body drops OVER the engine so all of anything attached to the engine has to be tucked out of the way so as not to interfere with that operation.
One neat thing about the service manual downloads at
www.mymopar.com is that several model years can be compared without having to spend money. Plus the diagrams of which plugs wires go where on which years and which models. There can be a good bit of cross-over between C and B-bodies in this area on some years. Other years, things can be completely different, as the exhaust manifolds changed between the two platforms.
Just some thoughts,
CBODY67