I just recently purchased a 1974 Plymouth duster with a 318 automatic. I purchased a Holley four barrel and installed it on the car. I am concerned about the existing linkage and don’t want to damage my transmission driving it. The Short distance I drove it to test the carburetor, I noticed the car hesitated shifting from 2nd to 3rd, and seem to downshift into second while coasting to a stop. (Like pulling the gearshift leverdown to second). Any advice on linkage set up would be appreciated.
Linkage set up on 1974 Plymouth duster with 318 automatic
- Thread starter gnagrant
- Start date
-
Professor Fate
Push the button, Max...
What did you use for throttle/kickdown linkage? *Looks* like stock 2 bbl. stuff to me offhand... that needs some mods to make it work right. The kickdown looks like it's waaay off.
@318willrun has some videos on the subject, as well as many threads on here- try these for starters:
318 4bbl upgrade. Help
1973 360 upgrades
MoparGal (Alexis B’s) 1975 Plymouth Duster Build
Do a search and you will find many more.
You need to get that sorted before you put any miles on it.
@318willrun has some videos on the subject, as well as many threads on here- try these for starters:
318 4bbl upgrade. Help
1973 360 upgrades
MoparGal (Alexis B’s) 1975 Plymouth Duster Build
Do a search and you will find many more.
You need to get that sorted before you put any miles on it.
The Chrysler linkage parts I purchased at the same time from Holley. I got the part numbers from the tech.. I think the arm itself might be for a two barrel. I’m sure not having much luck finding a Longer arm that might be a better fit
the back edge of the slot on the kickdown rod should be touching your throttle cable pin. it looks as though yours is at the front edge?
4 barrel throttle cable brackets can be bought at online vendors. Here's one from Mancini Racing
For the correct 4 barrel upper kick down rod, you'll need to find a member who has one for sale. You can buy reproductions but you have to buy all 3 pieces in the set unfortunately.
4 barrel throttle cable brackets can be bought at online vendors. Here's one from Mancini Racing
For the correct 4 barrel upper kick down rod, you'll need to find a member who has one for sale. You can buy reproductions but you have to buy all 3 pieces in the set unfortunately.
Please show us a close up photo. By not having the kickdown adjusted properly, You can burn the clutches out in your transmission in short order.
Professor Fate
Push the button, Max...
Your kickdown rod needs to be extended ~1 1/2" to get you in the proper adjustment range. Either fab a new one or cut and lengthen your existing one.
If you don't have a welder, the easiest way would be to cut the rod in the middle and thread it, then use a long coupling nut to rejoin the two halves, which would also give you an additional place to adjust the linkage. Then secure it with a jam nut.
BTW, you do have the correct carb linkage adapter on there, right? I can't tell from your pics...
If you don't have a welder, the easiest way would be to cut the rod in the middle and thread it, then use a long coupling nut to rejoin the two halves, which would also give you an additional place to adjust the linkage. Then secure it with a jam nut.
BTW, you do have the correct carb linkage adapter on there, right? I can't tell from your pics...
Last edited:
you could cut the end of yours off and cut threads into it. you could even make it longer by adding a coupler and some extra threaded rod.
eBay has one for a 340 but it's missing the slotted end. Mancini has one listed for a hemi but it should work
Yep, the stud needs to be at the back of the slot and not the front. You need to extend the rod that amount but you do need someway to adjust and fine tune. The slotted end that j.anderson pictured would work as long as your kickdown rod is the right diameter for rethreading. Here is a thread with good info, photos and part numbers. 2-Barrel to 4-Barrel Conversion
Ouch. That's a mile off as well. I'm surprised your transmission still works. Let me post up some more photos of how it should look. Like mentioned. The pin on the carb linkage should be at the back of the slot. The spring should be positioned to pull the rod against the pin at all times. A couple photos don't have adjustable slotted rods but there are adjustments on the linkage.
That's probably what saved it.
VOETOM
Well-Known Member
Don't forget to install the correct short throttle pressure lever on the throttle /shifter shaft where it sticks out of the case on the driver's side.
-
