73 Duster going from manual to automatic

-

Matt F

Active Member
Joined
Oct 15, 2019
Messages
44
Reaction score
14
Location
Colfax WI
Yes I know. WHY??? Well my wife and kids would like to drive this once in awhile so an automatic it is for now.
I have a 73 duster with a 225 manual on the floor. I will be putting a 400hp 71 360 in it. I also have a 76 duster 318 automatic as a donor. What other than a balanced 360 B&M flex plate should I be considering. Thank you in advance.
 
Things to consider: drive shaft length and yoke, shift linkage, kickdown linkage, radiator, motor mounts, exhaust. Don't know how much of this you'll have in your donor car. Pretty straight forward swap.
 
I should have everything in the donor just wanted to see if there were any surprises but seems pretty straightforward. Thank you.
 
Mechanicing on two old cars it's not going to be smooth...lol..
It's very doable though...
 
your very well set from the radiator back if the 318 runs fairly good I would do that first for trial once you go to the higher HP 360 you'll probably want to upgrade some stuff when you do it everything comes out and goes back in from the bottom hell if you haven't used them yet you have the disc brakes and possibly the 8.25 rear
 
Yes I know. WHY??? Well my wife and kids would like to drive this once in awhile so an automatic it is for now.
I have a 73 duster with a 225 manual on the floor. I will be putting a 400hp 71 360 in it. I also have a 76 duster 318 automatic as a donor. What other than a balanced 360 B&M flex plate should I be considering. Thank you in advance.
This: "Well my wife and kids would like to drive this once in awhile" is exactly why I want to turn my Cuda from an auto to a manual.. they won't want to then :)
Are you going to sell the stick stuff? I'm not far from you, interested if you are. I have some automatic stuff to trade too.
 
This: "Well my wife and kids would like to drive this once in awhile" is exactly why I want to turn my Cuda from an auto to a manual.. they won't want to then :)
Are you going to sell the stick stuff? I'm not far from you, interested if you are. I have some automatic stuff to trade too.
Yes I will be selling the 225, bell, and transmission.
I will be keeping the 4spd manual incase I get sick of the automatic. Never ran the 318 not sure how it runs but the 360 sends a vibration through your chest when fired up.
 
your very well set from the radiator back if the 318 runs fairly good I would do that first for trial once you go to the higher HP 360 you'll probably want to upgrade some stuff when you do it everything comes out and goes back in from the bottom hell if you haven't used them yet you have the disc brakes and possibly the 8.25 rear
Not sure if the 318 runs haven't tried. How do I know what rear end I have?
 
your donor 318 has either the 7 1/4 or 8 1/4 they would be big 4.5 bolt pattern
 
again your donor has everything to convert front to back and inside -- column - brake pedal on and on very easy swap
 
Yes I know. WHY??? Well my wife and kids would like to drive this once in awhile so an automatic it is for now.
I have a 73 duster with a 225 manual on the floor. I will be putting a 400hp 71 360 in it. I also have a 76 duster 318 automatic as a donor. What other than a balanced 360 B&M flex plate should I be considering. Thank you in advance.
This is hard to figure out 400 HP and making it an automatic so the "KIDS" can drive I can possibly understand the wife but ?
 
If that 400hp is with iron heads,then that will likely have a cam like the 292/509. And if you compression is not way up there then the take-off with stock parts will be sluggish.
So that usually leads to a hi-stall, bigger rear gears, and an overdrive. This means 2.76s is gonna suck with a 2000stall that the 318 car likely has; is all I'm saying.
But if you did your homework, then it won't be quite as bad as it sounds.
The trick is to have a reasonable amount of power in first gear at stall, and to have a lot of power when you nail it; For me that means 30 mph.

At KD into first (2.45 ratio), at 30 mph;
2.76s would be ~2650, so even a 2800TC is not gonna help you much.
4.10s would be ~3900, close to peak torque, so when you nail it,she will explode with tirespin.
3.55s would be ~3400, your compromise, and about as low as I would go with that 292 cam. But you're gonna need a bit of stall to go with that. The 318 TC is not gonna cut it.
Your results may vary.
An overdrive and 4.30s would be sweet, hitting 65 at about the top of second gear(1.45 ratio), ~5300, very close to the powerpeak. and she'll still cruise at 65=2400 in loc-up.(.69overdrive)

Just trying to be helpful; that 292 is not the most friendly cam I have used.
 
Thank you. Problem is the guy that had the motor built doesn't know much about it. I will have to look into a new TC.
 
This is hard to figure out 400 HP and making it an automatic so the "KIDS" can drive I can possibly understand the wife but ?

I also have accres to a mildly built 318 that would be more suitable for the teens. Easy to switch motors around after the initial swap has been done.
I have a 1972 318 has new rings and rod and main bearings in it also has a new Howard’s Performance hyd Cam and Lifters. Has new valve job on “302” closed chamber heads
 
I also have accres to a mildly built 318 that would be more suitable for the teens. Easy to switch motors around after the initial swap has been done.
I have a 1972 318 has new rings and rod and main bearings in it also has a new Howard’s Performance hyd Cam and Lifters. Has new valve job on “302” closed chamber heads
sounds like a no brainer to me
 
This is hard to figure out 400 HP and making it an automatic so the "KIDS" can drive I can possibly understand the wife but ?

Sounds like a good dad to me. :thumbsup: Good luck telling my daughter when she turns 16 that she can't drive the purple car.
 
-
Back
Top