the two barrel intake and exhaust off amc eagle, concord, so forth are all over the junk yards. I pulled the intake, exhaust, 2 barrel carb off the AMC for $35. Keep the monifold bolts off the AMC Car. New 80's manifold flange is 1/2" and your cast iron OEM manifolds hace 1" flanges so new bolts much shorter. Intake from 1980 or 1981 TARGET Year will not have a computer controled carb but excellent design. I found one 1980 but was Calf Car so had the pin feed back computer hook up.
This will make your jeep run better esp is you have single barrel set up, take off 40# of cast iron off your cj, and bolt right on and hook up to your 1976. Buy the gaskets for the 1981 because you need special materials to handle aluminum intake with cast iron head. I had a single barrel carb & intake so this was a great upgrade for me. I did not look at your profile about single dual carb.
Aluminu intake has water jacket heating and more uniform and has electric disk heater under the carb adn I have a post on how to hook that up with the Jeep Manifold Coolant Switch and a relay. Works well.
I have the Borla and like it but Borla told me would not fit on the 1970 CJ's but it does. I tried to get them to change their literature adn web site. Sent them may pics. Ihave the whole system and fits the CJ7, Cj5 is smaller and would need modification. May also need mod to bracket if you have power steering to clear the #1 exhaust. Borla header is $470 range, . Pacesetter and 1-2 others only option for headers. All big buck unless you find used.
The 4.0 headers are much less expensive but the 4.0 4.2 are not interchangable.