You can cut them at the cat, crush them flat and fold them over to seal it. More than likely that cat is plugged up, so you would benefit from the hi-flow cat.
If you have open vacuum lines, I'm surprised it runs. All you need are the lines running between the carb, CTO, EGR, evap canister and the distributor. Everything else can go. When I pulled all mine, I filled a 5 gallon bucket with hoses, solenoids and check valves. What a mess they designed.
1990 Jeep YJ Laredo 4.2 I-6
2010 Jeep JK Islander 3.8 V-6
1982 Jeep CJ-8 Scrambler 304 V-8