So I have a 1965 Mustang Fastback with a C4 automatic transmission that I am wanting to swap out for a toploader 4 speed. I need to know the specifics of what this swap will require. I know I am going to go with a hydraulic clutch, but other than that I have no idea. Does this require a new transmission cross-member? Any changes that would need to be done to the transmission hump for linkage clearance or mounting the shifter? Also, I am building my 289 stroked to 302 rather hot (about 450 HP) so would there need to be any modifications to the toploader? Also if any of you could suggest a good clutch that could handle the torque of a strong 302, it would be much appreciated. Thanks a lot for your help.
The finer points of a C4 to toploader swap
- Thread starter 65mustang289
- Start date
Also, if any of you would like to see my project, you can check it out at http://www.cardomain.com/ride/2541859.
dennis112
15 Year Member
I've done the swap a few times, using stock mechanical linkage. I assume you are talking about a 4 speed toploader (vs the 3 speed.)
The crossmembers are the same. No modifications are needed to the hump or the shifter opening, as long as you stay with either a stock Ford shifter (yuck) or get a Hurst Competition Plus (recommended.) Nothing on the body should need tweaked.
The Toploader is tough as nails and will need no strength modification to live behind a hot 289/302. Except for the input shaft and output shaft, the same guts and casing are found behind a 428CJ and the Boss 429.
You will want to purchase a Toploader that was made to fit a Mustang. Including the bellhousing, it will be the same overall length as your C4 and will have the correct mounting location for the shifter on the tailshaft. As long as the toploader isn't one of the early 64/65 type with a 25 spline outputshaft, your C4 driveshaft will work just fine. If you go here: http://www.davidkeetoploaders.com/idchart1.htm you will be able to match the toploader ID to its original application. Poke around on that site and you will become quite knowledgeable about the toploader.
Toploaders come in 2 basic flavors. A wide ratio and a close ratio. I recommend holding out for a wide ratio as it's lower first gear is desireable.
Although it may be considered overkill for you combination, I am very pleased with the Centerforce dual friction clutch. Low pedal effort, smooth engagement, and can handle brute force when needed.
One thing you may not have thought of is the speedo cable. Although the cables are generally the same, the one for the toploader will be longer as the speedo cable normally enters on the passenger side vs. the driver's side for a C4.
The crossmembers are the same. No modifications are needed to the hump or the shifter opening, as long as you stay with either a stock Ford shifter (yuck) or get a Hurst Competition Plus (recommended.) Nothing on the body should need tweaked.
The Toploader is tough as nails and will need no strength modification to live behind a hot 289/302. Except for the input shaft and output shaft, the same guts and casing are found behind a 428CJ and the Boss 429.
You will want to purchase a Toploader that was made to fit a Mustang. Including the bellhousing, it will be the same overall length as your C4 and will have the correct mounting location for the shifter on the tailshaft. As long as the toploader isn't one of the early 64/65 type with a 25 spline outputshaft, your C4 driveshaft will work just fine. If you go here: http://www.davidkeetoploaders.com/idchart1.htm you will be able to match the toploader ID to its original application. Poke around on that site and you will become quite knowledgeable about the toploader.
Toploaders come in 2 basic flavors. A wide ratio and a close ratio. I recommend holding out for a wide ratio as it's lower first gear is desireable.
Although it may be considered overkill for you combination, I am very pleased with the Centerforce dual friction clutch. Low pedal effort, smooth engagement, and can handle brute force when needed.
One thing you may not have thought of is the speedo cable. Although the cables are generally the same, the one for the toploader will be longer as the speedo cable normally enters on the passenger side vs. the driver's side for a C4.
ratio411
Founding Member
Great info they gave...
I'll add one other fine point that will be a decision you will need to make.
289-302s originally came with 10" clutches and smaller flywheels.
When I convert my cars, or when I get a car with the 10" clutch, I upgrade to the 351 bellhousing and flywheel. They utilize an 11" clutch/flywheel combo.
Bolts up fine and other than being slightly larger, works great.
The stock 10" bell is aluminum, while the 11" bell is iron.
So the bell is definately heavier.
I don't know if it is safer. Some say yes, some say being iron it will shatter in a clutch explosion, offering no protection.
The truth is probably somewhere in the middle, aluminum vs iron.
If you go with a steel bell, like Lakewood, they can use 10",10.5", or 11" clutch/flywheel... However to use the 11", they recommend setting it up with adjustable dowels and a dial indicator, because it is an extremely tight fit.
I have only ever used this bell once, and used the 11", without setting it up like this. It did great, but I just may have been lucky.
Anyway, what I am getting at is:
If you are building a hot engine, you will want an 11" clutch to get that much more holding power.
I use an 11" counterweighted Centerforce with a Hays billet flywheel, all behind a very mild 302.
Also, the starter will be slightly different for your swap too.
It looks almost identical, but the gear travels slightly different, so get a new starter too.
I know it has already been impressed upon you, but I will say it again, use an SBF toploader from a Stang. Wide ratio...
Check the crank bushing part of the input shaft especially!!!!
Many folks will try to pass of a 390 toploader as a 289/302!!!
They are identical except for the input nose.
The FE tranny has a crank bushing surface about 7/8" in length, while the SBF MUST have about 1 1/16" (IIRC) nose length.
The crank bushing surface is longer. Not wider, thicker, or anything else, just longer.
Good luck
Dave
I'll add one other fine point that will be a decision you will need to make.
289-302s originally came with 10" clutches and smaller flywheels.
When I convert my cars, or when I get a car with the 10" clutch, I upgrade to the 351 bellhousing and flywheel. They utilize an 11" clutch/flywheel combo.
Bolts up fine and other than being slightly larger, works great.
The stock 10" bell is aluminum, while the 11" bell is iron.
So the bell is definately heavier.
I don't know if it is safer. Some say yes, some say being iron it will shatter in a clutch explosion, offering no protection.
The truth is probably somewhere in the middle, aluminum vs iron.
If you go with a steel bell, like Lakewood, they can use 10",10.5", or 11" clutch/flywheel... However to use the 11", they recommend setting it up with adjustable dowels and a dial indicator, because it is an extremely tight fit.
I have only ever used this bell once, and used the 11", without setting it up like this. It did great, but I just may have been lucky.
Anyway, what I am getting at is:
If you are building a hot engine, you will want an 11" clutch to get that much more holding power.
I use an 11" counterweighted Centerforce with a Hays billet flywheel, all behind a very mild 302.
Also, the starter will be slightly different for your swap too.
It looks almost identical, but the gear travels slightly different, so get a new starter too.
I know it has already been impressed upon you, but I will say it again, use an SBF toploader from a Stang. Wide ratio...
Check the crank bushing part of the input shaft especially!!!!
Many folks will try to pass of a 390 toploader as a 289/302!!!
They are identical except for the input nose.
The FE tranny has a crank bushing surface about 7/8" in length, while the SBF MUST have about 1 1/16" (IIRC) nose length.
The crank bushing surface is longer. Not wider, thicker, or anything else, just longer.
Good luck
Dave
dennis112
15 Year Member
Sacramento6
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ratio411
Founding Member
Is the 10.5" clutch set up on the 10" bolt pattern, or do you need a dual pattern flywheel?
I have heard of folks swapping between the two.
I just haven't caught the details about the need for a special flywheel or anything like that...
Dave
I have heard of folks swapping between the two.
I just haven't caught the details about the need for a special flywheel or anything like that...
Dave
dennis112
15 Year Member
I don't know if it is mentioned yet, but the starter is different between a C4 and a 3 or 4 speed toploader car. Must get the right one or change the snout, because it is different.
A T5 conversion could use the same C4 starter.
A T5 conversion could use the same C4 starter.
I'm using a late model 5.0 flywheel. The one behind the 331 has been rebalanced to 28 oz. Bell is a late 60's Toploader. 10.5" clutch.
ratio411
Founding Member
Hurst shifters are universal.
What bridges the gap between tranny and universal shifter is the install kit.
So, get the right install kit for your tranny, and you can put most any shifter on it.
Dave
What bridges the gap between tranny and universal shifter is the install kit.
So, get the right install kit for your tranny, and you can put most any shifter on it.
Dave
I assume here, he's talking about a Borg Warner T10. Yea, Hurst made shifters for these too. But the Comp Plus and others aren't completely interchangeable (the shifter itself) Different transmissions used different shifter body's.
dennis112
15 Year Member
Some comp plus shifters have welded on handles which are specific for certain cars. Other comp plus's have bolt-on handles that allow you to swap different handles.
The handle for the mustang has two 90 degree bends just as the handle exits the shifter body.
The handle for the mustang has two 90 degree bends just as the handle exits the shifter body.
And the reverse lever under the shifter has a 90* dogleg in it.Thanks a lot for the input. I'll keep all of that in mind as I get closer to the completion of my fastback. Shouldn't be a whole lot longer now, needs paint, interior, and I have to build the engine, for which I have most of the parts. The hardest part is done. Thanks again for all the help.
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