4 speed versus 5 speed trans

65fastbackresto

Active Member
Apr 13, 2007
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I`m about tired of my c-4 tranny, its a peice of crap and leaks like crazy. I am weighing my cost of changing from auto tranny to manual tranny, and how much trouble its gonna be. Heres the deal, I currently have factory 6 cyl car thats been converted to a v-8 with a c-4 trans.

I`m wanting a stick shift, but dont know how to start. A 4 speed or 5 speed would prob work, but I need some opnions on each. I would also like to know final cost ( parts only) of such a project from start to finish. (I`ll need clutch peddle and all parts but can do the work myself).

Ballpark numbers would be fine, I would like a tranny that will hold up to a sidestepped clutch sometimes though...........

Thanks in advance.
 
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I was in the same situation 2 years ago. V8 converted car with a C4. I ended up going with a T5 and cable clutch. Sent my pedal to Mustang Steve and he added a clutch pedal, and did all the modifications to it for ball bearings, cable, etc. Had the driveshaft shortened, engine was stock and slow, so i went with a ~$100 autozone clutch.

In the end, it costed me $1200 max, closer to $1000 including the T5. Was definitely worth it. But now its a different engine, and a TKO is in need...
 
I thought that was a T-5 of a sort.....

My motor is built a little, and I like chirping gears if I can do it without killing something......


Since the C-4 (although leaky) is in place, you can at least continue to drive the Mustang. Once you decide on what transmission to go with, you could buy parts here and there until you had everything needed to make the swap over.

This is the same thing I did back in '87 when the (second) C-4 in my '68 was starting on it's way out. When the C-4 finally died, I had all the components to swap it over to a (wide ratio) Top-loader 4-speed.

Several years ago, I bought a wrecked '90 Mustang GT to get the fuel-injected 5.0L engine, T-5, etc. out of to swap over into my '68. My '68 is currently just a hull, but when the time comes to put it back together, I'll have all the needed components waiting to be installed.

...I see that you live in the western part of the state (Arkansas). I live in the south-central part --Camden, AR. :nice:
 
A Toploader will last forever in a lightweight smallblock Mustang, but it will definitely cost more and has no overdrive. However, I think a 5.0 T5 will also take a decent beating in the same car because of the lighter chassis. Keep in mind that the average '87-95 5.0 is 3200-3400lbs and they last a fairly long time in those. Add some gears like 3.50s and it will be even better. Get an aftermarket shifter for the T5, though; the stockers suck.
 
To further add to 65ShelbyCone's info on a Toploader-------the one I have in my 89 Ranger is a 68 model, still going strong after 39 years and it's never been rebuilt. I'm going thru the same crap with my 77 Comet. 2 runs---- remove and fix the C-4, 4 runs----remove and fix the C-4 (tomorrow it comes out again) I'm about to find a C-6 for it and be done with this ****.
 
So a TKO is a toploader right?

And what does wide ratio mean? Tall gears maybe?

Why would they call it a toploader anyway?

Ultrastang, you are the first guy I`ve seen on here also from AR, cool man.
 
And what does wide ratio mean? Tall gears maybe?

Why would they call it a toploader anyway?
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A TKO is a Tremec Heavy duty 5-speed transmission.
They come in a few varieties for your specific application.

The problem with them in classic mustangs is that their may or may not be some modifications to your transmission tunnel to get the proper pinion angle.

Top Loaders are called that because the gears are accessed from the top of transmission as apposed to the side. Very easy to spot just don’t confuse a 3-speed top loader with a 4.

Wide ratio or close ratio refers to the gear ratios of the tranny. A close ratio will have less of a drop in rpm from gear to gear and a wide will have more.

I have a Top Loader in my car and Like D Hearne and Shelbyclone said, NO PROBLEMS. They are bullet proof behind small blocks.

I would suggest going to a 5-speed.
A question you need to ask yourself is How much power you intend to have?

If you plan on a mild buildup then T-5 will be just fine.

If you plan on a lot of power or slicks for drag racing and don’t want to worry about your trans then go to a TKO or G-Force T-5.
There is also a Richmond Gear 5 speed (overdrive) but very pricey.

I might be swapping out my Top loader for a 5 speed in the spring.
 
A Top Loader doesn't always cost more. I went through a similar debate in my mind when I was switching from a 3 speed manual. I wasn't sure if I wanted a Top Loader or T5. I finally went with the Top Loader because I wanted my car to be as original in aperance as possible. I picked up a nice Top Loader from E-Bay for $695.00 It was even from a 66 Mustang and the numbers were correct for my car and my year. The transmission is in great shape and all I did was install it, put in a hurst competition plus shifter, add gear lube and I was on my way. You can pick up used Top Loaders or T5 transmissions for around the same price if you are patient and look around. The real question is how are you going to use your car? If you will be driving it a lot a T5 will make it a lot of fun to drive and save you gas. Since your car is already modified with a V8 instead of the original I6, I would seriously think about a T5. Either way, you'll enjoy shifting it yourself a lot better than the slush box. I did the same C4 to Top Loader swap 20 years ago. It was easy, all Ineeded was the trans, clutch and associated parts (Z bar, pedal etc...) manual trans support bracket and it went in nicely. I did have to bypass the automatic transmission shifter engine lock out switch, but that was simple.
 
Blu-Steel

How did you bypass the switch? I`ve heard of people having big issues getting around that thing, your talking the neutral satety switch right?

You guys are alot of help, I wish I had not spent all this money on this c-4 now, I could have been real close to done with the 5 speed by now. money wise anyway.
 
My vote if for the T5 for your application. I'm running a toploader 4sp in my car now w/ 3.80 gears. It's fun at the strip and I have been powershifting and seems to
hold up well. Of course it's only a 13 sec car. I do have a 1993 version of the T5 that going in at some point once funds allow. If you go w/ a stock T5 try and get one from the 90-93 models as they are rated up to 300 lb ft comparted to the
earlier models which were 265 lbs. I can't wait to hava a overdrive as 3k rpm at 60 really does suck for any length of time. Unless you planning on ripping off 11 sec times and bang gears I think the aftermarket units are just overkill. I've spoke w/ many folks who have had years of good service w/ stock T5's and some were pretty fast...
 
Wide ratio Top-Loader 4-spds. have a 2.78:1 1st gear and are 1:1 in high gear.

A Close ratio 4-spd. has a 2.32:1 1st gear and are 1:1 in high. --2nd and 3rd gears also have slightly different ratios in the wide ratio vs. close ratio transmissions.

The T-5's neutral safety switch will play no role when used in an early Mustang application --unless you elect to hook it into the neutral safety switch circuit. In that case, you would need to mount a switch on the pedal support to active when the clutch pedal is pushed in to enable the starter to engage.
 
I thought if you unhooked the wires

to the tranny neutral safety switch, that the car wouldn`t start at all, that the circuit wasnt complete or something, I may very well have misunderstood this though.

Sounds like if I went the 4 speed, the close ratio would be more fun....
 
I ran a 1987 T5 behind a '69 351W for a couple of years in my '67 coupe. The 2.79 gears gave me rediculous highway mileage.... waaaaaaaaaaaaay more fun then the C4.

It cost me $700 for the tranny, shifter, flywheel, clutch, clutch pedal. I had to get the flywheel resurfaced and balanced, but other than that the tranny bolted to the crossmember, I used the stock driveshaft, and made the fox body clutch pedal and cable work with the stock '67 pedals.

The good used clutch held up fine with a little abuse. Never had an issue with the tranny... but then again, I had an open rear and never ran sticky tires.

The same people that say that T5's are weak are the same ones that say you can't run a single plane on the street... it's all about what you expect out of your car. Maybe I just have lowered expectations...