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Discussion Starter #1
I'm going to look at a few toploaders tomorrow, and in the Craigslist ad, there were two different bellhousing bolt patterns. I'm wondering if these patterns are engine specific. For instance, is one only used with 5-bolt bellhousings, while the other is compatible with everything else? My car is a 6-bolt block.

Also, is there anything super expensive that can go wrong on a toploader, provided the gears are fine? And what do I look for on the tag for identification? I'd like to get a close-ratio 4-speed if possible. Lastly, if it is a larger 1-3/8" input shaft, can I just use a different clutch to mate it to my 289?
 

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Discussion Starter #2
I have confirmed that the narrow trans-side pattern is for the 5-bolt bellhousing, while the wide pattern is for the 6-bolt. There are some transmissions that have both patterns, and some bellhousings that have both, while others can be drilled and tapped. Still, I'm going with a wide-patterned trans regardless. I'm reasonably sure that any 10.5" clutch with a 1 3/8", 10 spline input will work, if I do end up with a large input shaft transmission.

Could still use some clarification on ratio I.D., though.
 

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Paul, I'm not an expert on the toploader, but I have driven my 65 that has one, off and on for 40 years, unless you are racing it, you will be happier with a wide ratio, that is what I have, the benefits are about .5 more ratio in 1st gear, thats like having a 3.5 ratio diff versus a 3.0 ratio diff in effect. And in driving it, when getting on the freeway, I use all 4 gears, but just driving around town, I usually go 1,2,4 or 1,3,4. I had driven a 66 GT 2+2 with a 289 271HP and a close ratio with 3.89:1 diff and it was a lot of fun back in the 70's. Here is one web site on toploaders: Ford Transmissions You might google some others, there is like either 200 or 400 different ones, so you need to figure out which models you need for your engine, otherwise you could wind up with one for a 390 or an I6. My 2 cts. Good Luck.
 

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Paul, Rex is spot on, you would be just as happy and better served with a wide ratio toploader.

As for the 1-3/8" input shaft size, most of those were for Big block cars. The end of the shaft (pilot) would be too short for your small block. You can use a small block input shaft in a small block and a big block ford but you can't ("should not") use a big block input shaft in a small block. I say "should not" because you can buy an extender for the shaft end but I don't recommended it at all.

The bolt pattern on the toploader is either a single or dual pattern. Only the early 65 was a single pattern. But both will work. You have to watch because the early transmissions (65) only had a 25 spline out put shaft and you'll need a different yoke for your drive shaft.

To me the biggest thing to pay attention to is to make sure it has the correct size input shaft (1-1/16") and the tail shaft housing is the correct length for your car (14") anything longer may require a special length drive shaft

The bell housing and bolt pattern are the least of concerns.
 

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Discussion Starter #5

The one I'm looking to get is the second from the right. It does appear to have the longer input shaft, and the rear-mounted shifter, which looks correct for the Mustang. I do some autocrossing, and hope to do some open track days, and my 289 likes higher RPMs anyways, so I'm hoping that it's the close ratio, but I won't be heartbroken if it's a wide ratio. I'm also OK with shortening the driveshaft if need be. It's a couple days in the shop, and not much money out of pocket.

I'll keep studying up on them; don't want to screw this up after all.

Thanks!
 

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You have chosen.....wisely...for a 6-bolt bellhousing! It appears to be exactly the same gearbox as that which is languishing on my garage floor after many years of faithful service in a 67 289 fastback and then behind my 69 250 6-cyl. It is in all likelihood a wide ratio, but you will be very pleased with the results. If you can read any stamped numbers off the case, you should be able to determine ratios.




Disclaimer; this is MY OPINION only; there are better informed members that may reply to your inquiry.
 

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The one I'm looking to get is the second from the right. It does appear to have the longer input shaft, and the rear-mounted shifter, which looks correct for the Mustang. I do some autocrossing, and hope to do some open track days, and my 289 likes higher RPMs anyways, so I'm hoping that it's the close ratio, but I won't be heartbroken if it's a wide ratio. I'm also OK with shortening the driveshaft if need be. It's a couple days in the shop, and not much money out of pocket.

I'll keep studying up on them; don't want to screw this up after all.

Thanks!
TWO THINGS:

You are referring to the second one from the right in your picture which is also the one that's farthest forward (just so we are clear).

1. I cant see the tail shaft housing clear enough so its not possible to tell you if it will place your shifter in the correct location or if an adapter plate will be required.

2. Make sure the connection for the speedometer cable is on the passenger side of the tail shaft housing. If its not, its more than likely a 3-speed with overdrive and not a 4-speed toploader.
 

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Discussion Starter #8


Bought the trans. It was $300, and everything is in working order. Came with a shifter, equalizer linkage (it was free, but I'm not sure it'll fit), and a clutch fork. According to the tag, it most likely came out of a '67 Fairlane with a 390, but it has the smaller input shaft, so it should still fit a small block. I noticed it has two positions for the shifter, so it'll probably fit just fine.

If for some reason it doesn't work, I can still make money on the deal.
 

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Now that I can see the tail shaft housing from the side, I'm fairly certain the transmission you reflect in your most recent photo's is a late 70's top loader (78 - 79). More or less the overdrive type.

Someone may have changed the internals to convert it to a true four speed but I don't know.
 

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Discussion Starter #10 (Edited)
I've been really curious about the CB tag myself. I was thinking it might be the so-called Imposter trans, but as far as I can tell, there's only four of them, and they are RUG-CA, CD, CL, and BP. Some people are saying that cases with ORION cast into the side (like mine has), are overdrive transmissions. But it does have the 4-speed tailshaft, and I don't remember seeing an overdrive gear so it very well may be a converted version.

Edit: It was an overdrive unit. There's a large rib around 3rd gear, which other Toploaders lack. Tomorrow I'll pull the cover to see if it was converted. It would be nice to have an overdrive, but a 4-speed OD trans would make for some pretty awful gear ratios to make it work with my powerband.
 

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Discussion Starter #11
Took a look inside the trans, and it is, in fact, an overdrive. A buddy of mine says it's a Single Rail Overdrive, which I believe references the shift fork rail arrangement.

Not what I was expecting, but I do lots of freeway driving, so this'll be pretty nice. Sure, it'll be a tad lethargic with 3.08 gears, but it does have a deeper 1st gear than the C4, and I can always upgrade those later on.
 
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