All Small Six C4 vs Toploader 4-speed

[Crustang to Mustang]

I originally started off wanting a T5 but I know that this conversion requires a custom crossmember and I saw where someone mentioned a custom driveshaft?... Not to mention the price of a good T5 in my area... I already have a C4 so that's an option but I kinda want a manual. So this is my question: Is it worth swapping to a Toploader 4-speed or is a C4 with a shift kit better since I already have the C4?

 

[aussie7mains]

Manual trans every time, especially with a small displacement NA engine. doesnt matter how good a C4 is, its always got the disavantage of the torque convertor, IMO only good with stock higher torque engines, or for drag racing. C4 and 250 works. The t5 would be nice. Here in Australia toploaders run to around $2500-3500, which is quite a lot. Were lucky we have an Australian made 4 speed about equivalent to a toploader, but much cheaper. Some of the japanese 4 speeds would work, but you need custom bits for that. Dagenham? They should be OK when in good condition.

 

[John Ha]

Personal preferences vary so you're the one to make the decision. A lot of us prefer the manual shift over the automatic, but many others, as evinced by the fact that it's all but impossible to find a manufacturer selling a manual shift car these days.

If money is the driving point behind the decision, a shift kit is the right choice since you don't need the bellhousing, clutch, flywheel, transmission, clutch actuation system, pedal, etc.

Toploaders are expensive - in the same general range as a new T5z. The crossmember for the T5 isn't all that much ($270-ish). I didn't have to change the driveshaft when I went from a C4 to the T5, but others have had to. I don't know what differences in configuration would drive that change but some have had to have the driveshaft shortened. A good driveline shop can do that. If you go with the T5 there's also the choice of which clutch actuation system to use - Ford stock Z-bar, cable or hydraulic.

 

[DON]

Be aware of the process of adding a clutch pedal. Watch a video and then look under your dash. I don’t want to discourage you but but just know what you’re getting into. Also the return springs are very strong- difficult to install and remove. If you do go that route, upgrade the pivot point to the bearings as well as make sure the insulators under the ends of the springs are in place ( where the springs pull on the support and pedal ) if not there it will squeak. I don’t know of and hacks for installing those springs. ???

 

[frozenrabbit]

Not ideal gear ratios in a 4-speed top loader for a small 6.

I have been trying to find info to set up a M5OD-R2 (mid 90's Ford V8 5 speed) for a 250. Same bell housing mount as a V8.

 

[powerband]

$ .02 more :
.
final drive ratio with both Toploader 4 Spd and C4 3 Spd is 1 :1 to Driveshaft. Late 60's and 70's small block six cars sacrificed performance with tall rear gears to keep RPM's manageable with new Interstate travel speeds.
.
for 'modern' acceleration needs and interstate Drivability above 70 MPH interstate Cruise speeds an OVERDRIVE tranny is simplest solution.
.
AFAIH - are there really no automatic-overdrive bolt-on possibilities available for the small block six?. (AOD ?)
.
T5 overdrive is so far simplest option to upgrade overall modern drivability of small six cars.
.
'61 250 Tri-Power has 3.80:1 posi gears, with T5 OD can safely drive to the track @ hour and half away at Thruway cruise speed. ( close to 1/4 end speed ! )
.
the '63 170 Falcon longroof evolved through 3 on the tree to a Dagenham 4 Spd and finally an 80's NWC T5 rebuilt for $200. 4 spd Dagenham had great gearing and 'Hypo" lockout shifter but lacked cruise speed with OEM 3.50 :1 rear gears. T5 gearing can match most six builds and lower ratio OEM rear axles match T5 gearing.
. .

.
... I never learned to drive them automatics' ...
.

 

[Invectivus]

IMO, measure twice and cut once. I converted a manual 3 speed to a C4, then to a T5. It was a big waste of time and effort but I did it for expediency. I grabbed a couple T5s from a junkyard and in my limited driving before blowing my head gasket, they were fine. (one leaked at the drain plug and it was a surer bet to swap). Also, getting a C4 into a car, for me, was WAY harder than a T5. The T5 was (almost) fun.

 

[frozenrabbit]

AFAIH - are there really no automatic-overdrive bolt-on possibilities available for the small block six?

I think Crustang is running a 250. Word is that an AOD behind a 250 just kills the power output.

 

[bmbm40]

I originally started off wanting a T5 but I know that this conversion requires a custom crossmember and I saw where someone mentioned a custom driveshaft?... Not to mention the price of a good T5 in my area... I already have a C4 so that's an option but I kinda want a manual. So this is my question: Is it worth swapping to a Toploader 4-speed or is a C4 with a shift kit better since I already have the C4?

Better for what do you have specific performance goals. Like 0-60 or top speed requirements.

 

[Crustang to Mustang]

I am currently considering turbocharging the 250 if that info is of any use in this discussion.

I am also pretty sure that the 8" that I have has 3.55:1 gears that I will definitely be using for now. But I am thinking of putting 3.80:1 gears in when I get the chance if that is still a good option.

My donor car does still have some of the clutch assembly still on it as well.