Is it possible to configure Autopilot to control route but not altitude?
The thing is that I want to drive Oil Burner routes but the lack of navigation aids makes this dificult.

Yes it is. To stop it from holding the Altitude, don't turn on the Altitude Hold Switch (#3 in attached image). Then it will still follow the route, but you will control the altitude. I tend to do the reverse, have the A/P hold the altitude, while I control the heading!

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Yes me to, but when flying at 500ft TACAN route it is best for AP to control the course, and it doesn't work for me, when I turn of the Altitude hold switch the Joke is not moving.

[autopilot]
autopilot_available             = 1
flight_director_available       = 1
default_vertical_speed          = 1800.0
autothrottle_available          = 1
autothrottle_arming_required    = 1
autothrottle_max_rpm            = 99
autothrottle_takeoff_ga         = 1
pitch_takeoff_ga                = 8;
max_pitch=10.0
max_pitch_acceleration=1.0
max_pitch_velocity_lo_alt=2.0
max_pitch_velocity_hi_alt=1.5
max_pitch_velocity_lo_alt_breakpoint=20000.0
max_pitch_velocity_hi_alt_breakpoint=28000.0
max_bank=25.0
max_bank_acceleration=1.8
max_bank_velocity=3.00
max_throttle_rate=0.05
nav_proportional_control=16.00
nav_integrator_control=0.17
nav_derivative_control=0.00
nav_integrator_boundary=2.50
nav_derivative_boundary=0.00
gs_proportional_control  = 18.0
gs_integrator_control    = 0.33
gs_derivative_control    = 0.00
gs_integrator_boundary   = 0.70
gs_derivative_boundary   = 0.00
yaw_damper_gain = 1.0

Are you sure you are using it correctly? In the ‘B-52 Driver’ FLIGHT MANUAL Part II – Aircraft and Systems (csb521_manual2.pdf), page 47, has this to say about the Nav Mode Selector Switch:

The rotary switch has TACAN-VOR-ILS-ILS APP positions.
· In TACAN position, the bank steering bar will respond to the MSFS flight plan (if loaded).
Note: Nav Mode Selector Switch is active only if Heading Selector Switch in NOR position.

I'm not sure how you are trying to use TACAN mode, but as you can see, TACAN mode only follows an MSFS Flight Plan.

I want AP to control the turns while I control the altitude. (When I turn the Heading hold switch to OFF, I want to control the altitude, if it is possible)
What is the difference between NAV and NOR.