Some good news, I have for you (. . . I think).
I don’t know how many cruise control changeovers I’ve worked on, on these cars over the years (hundreds, maybe).
If you currently have (or going to) a super six, then almost ALL cruise components from any ’77 (B, C, F or M body) vehicle are the same (except for PU or van – and even then there is a good chance most of it may be the same).
PU and vans are mostly the same. 1-bbl /6 have different throttle cable length.
Somewhere between ’79 and ’84, the cruise actuator and its mounting bracket changed – but if you change the actuator and bracket as an assembly, then everything works fine.
The way to tell the ’79 down actuator is it is mostly metal/metallic.
The ’84 up actuator has a good percentage of plastic in the housing.
Some (not all) turn signal handle/switches are different (non-tilt, tilt or tilt & telescopic (C Body)) but not true in all cases.
The newer steering columns ('80-89) have a different style for the cruise switch than the earlier ones ('76-79).
Parts you need for the changeover:
- Stop light switch and its bracket,
- Cruise actuator and its bracket.
-The cruise cable, the brake booster cable bracket, and the L shaped bracket by the throttle cable clamp.
- The carburetor pivot pin and black 1 inch long link on carburetor throttle shaft.
- Both sides of speedometer cable (to speedo head and to transmission).
Note: the length of speedometer cable is the same for ALL rear wheel drive vehicles except for Vans – but there are some minor differences.
- - '68-90 Chrysler (ALL rear wheel drive) the cable from actuator to speedometer head (has a white clip that attaches to back of speedometer head). ’67 and down has same length but cable screws onto back of speedo). Somewhere after ’90, the speedometers went electric (no cable).
- - ‘75ish-90 (ALL rear wheel drive) the lower cable is the same. The ‘75ish and down have a different attachment at transmission (it screws on instead of clips on). I much prefer the older screw on transmission adaptor to the clip on.
- The cruise switch.
- Wiring harness (standalone harness). Harness fits from ’60 to the new style steering column (‘80ish) and then new steering column to on (‘80ish to ‘92ish) for everything.
- Vacuum hose from brake booster (should have valve already on booster, just pop off the cap and run the hose.
Bad news – getting the cruise switch wiring ran down the steering column – um, is not a fun job.
The rest of it is straight forward.
F-body /6
F-body 318 (360 4-bbl slightly different)
B-body (Same parts – different view).
I happen to have a ‘84ish M-body Mopar Cruise install kit that I bought off of eBay about a year ago – but the cruise switch is for the new style column (and uses newer style servo/actuator). It has install instructions I can copy (if wanted) – but I do not have plans on selling it.
The new style and old style actuator work pretty much the same way. The newer style is a bit larger (and lighter – I think, not measured to find out). Also, the newer actuator steps in smaller increments (I think – no facts to back this up).
With the corresponding mounting bracket (which is different between the two) the two actuators can be interchanged.
Be sure to get the correct FMJ cruise actuator bracket. Should look like red arrow (above) – if old style actuator.