These were basically old lady transmissions guys, and as far as I am concerned they all shifted like old lady transmissions stock.
Of course there are things we can do with them to fix that, assuming it is adjusted correctly from the start.
This can be looked up online, but the basics are that you want zero travel left in the throttle pressure linkage at full throttle.
Lengthening the adjustment of the throttle pressure rod is one way of making later shifts but at some point you will keep the throttle from opening all the way doing this.
Shift kits are the most common change available for these old girls and they make a huge difference, but there are a couple of other simple things available to us.
Firm quick shifts are a result of a higher volume of fluid getting to the clutchpacks or bands quicker and this can be done to a point by upping the line pressure via the throttle pressure rod adjustment, but this only has so much it can do.
Later shifts are a function of the governor (mostly) and the speed that the driveline is turning, since the governor is mounted directly to the output shaft of the trans (that splined shaft in the back of the trans the driveline slides onto)
The faster the driveline turns, the more the trans wants to shift, and there are kits that we can buy to change that.
Basically it's a kit that makes the governor valve resist moving until a higher driveline speed is reached. (this is called "shift points") as in where in mph the trans shifts.
Other pressure in the trans come into play also but this is the basics of it.
Upping the pressure via the throttle pressure adjustment basically tells the governor to wait for higher driveline speed before it allows a shift.
This has a little effect on the shift firmness because the pressures are a little higher allowing more volume of fluid to get to the clutches and bands faster to apply them.
If a person ONLY wanted a later shift then the governor kit would be a good place to start.
It can be modded in it's stock form to do the same thing, but you should consult someone who knows how to do it before attempting this or you could end up with a trans that doesn't work any more until you get a new governor.
Remember I said you can adjust the TP linkage to somewhat change the shift points and firmness but only so much before it causes other problems?
Well some people put a bolt and nut through the slot in the TP linkage to make the TP rod travel farther ahead of the throttle travel.
This does work, but the problem is that you will no longer be able to open the throttle all the way, because the TP rod will hit the end of it's travel before the throttle does.
It will however move the shiftpoints higher in the RPM and MPH range at off idle and mid throttle speeds.
It will NOT change where the trans shift at higher throttle openings though (the governor does that, remember?)
The solution to that is taking some weight off the governor valve to make it lighter, and therefore less affected by the spinning forces of the driveline speed, or adding spring pressure to resist the valve from moving longer/later in RPM's
In the old days adding another half of a spring in with the original governor spring was about perfect for this.
This is what the governor kits do. (Lighter valve or more spring)
It can be done without the kits, but you need to know exactly what you are doing and why it makes the difference.
It may even take some experimenting (as in pulling it multiple times to make changes)
The firmness of the shift if you remember are more a function of fluid volume (how fast you can get the fluid to move into the clutchpacks and band apply servo's)
So knowing all this, you can make the hole that the oil flows through in the plate between the two halves of the valvebody bigger (more flow volume) for each gear.
This is one of the things the shift kits instruct you to do when installing them.
So making the governor wait longer/later in RPM's to send the oil, and the holes the oil goes through bigger you just made the shifts later and quicker.
They will also be firmer due to the higher throttle openings causing the pressures in the trans to be higher.
Now, there is a solution for higher firmer shifts that does not require a shift kit, opening up the trans, or grinding on your governor.
It is VERY easy to do, but will only help the low and mid throttle shift points.
Remember what I said about putting a bolt and nut in the slot on the throttle pressure rod (that it will bottom out before the throttle opens all the way)
That is because it is a solid stop.
Here is a solution I came up with for that.
It is a simple spring connected to the throttle pressure rod with the other end connected to the throttle linkage pin that moves the rod.
All it does is cause the throttle pressure linkage to lead the the actual throttle opening.
It also allows the throttle to open fully unlike the bolt and nut solid stop I mentioned. above.
With the spring installed the trans thinks we are already doing ten MPH before the car ever rolls.
So if your trans made the 1-2 shift at 10 MPH before, it'll wait till 20-25 to shift now, and be firmer/quicker about doing it.
The spring will give as the throttle is opened more, and not limit your wide open throttle.
10 minutes and a spring (later firmer shifts) at low to mid throttle openings without limiting the full throttle travel.
I did a quick webpage with pictures about it a few years ago.
That is at the link below.
You will notice this was my old original carb but it all works the same on any carb with this type of linkage.
www.letsgocomputers.com/shifts.htm
Have fun
I figured I would give the results of my own after doing this.
I drilled the 1-2 shift oil passage in the separator plate to 1/8 inch, blocked my accumulator and added the spring to the linkage.
At light cruise throttle my car makes the 1-2 shift at about 15 mph and the 2-3 at about 30.
At mid throttle it makes the 1-2 shift at about 25-30 and the 2-3 shift at about 45.
Also at mid throttle I sometimes get a light tire bark on the 1-2 shift
At full throttle I shift it manually if I want higher/later RPM shifts (because I didn't change the governor valve or spring)
