Treblig
Well-Known Member
What's an easy way to tell whether a 727 is small block or big block. I can get this one for $25 and just can't pass t up. It has a counterweight on the tail.
Treblig
Treblig
Big Block OR Small Block 727????
- Thread starter Treblig
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360duster
Well-Known Member
to me it looks like a BB 727.....The SB one has got the starter in a little lower location. AFAIK at BB Trans the starter is about same height as the input shaft, SB Trans starter is below input shaft, S6 starter is higher than input shaft.
Michael
Michael
Treblig
Well-Known Member
Thanks Michael,
I was hoping someone could decipher the casting numbers on the side. But, I agree, it does look like the starter area is about in the middle. I guess I'll have to get the stamped numbers on the front rail driver's side??
Treblig
My call would be a small block.
Look at the holes below in red.
If the distance from the front of the square to the front of the hole is close to 6", it is a small block,
If the distance is less than 6", then it is a big block trans.
I couldn't find the number in the listing, but it seems to be of the 74 - 75 vintage, mostly the '74...
Look at the holes below in red.
If the distance from the front of the square to the front of the hole is close to 6", it is a small block,
If the distance is less than 6", then it is a big block trans.
I couldn't find the number in the listing, but it seems to be of the 74 - 75 vintage, mostly the '74...
This is correct, I remember measuring the trans that came off my 360 and the top two bolts were about the same distance, where the big block trans I had sitting beside it had a very small distance between.
Treblig
Well-Known Member
The spot you picked (on the left side) to draw one of your lines goes to a square casting hole. The actual bolt hole is further to the left??
Treblig
Like I drew it, from the square hole across to the round hole on top. Either measure front to front or rear to rear of hole for the 6". Not round hole to round hole, I would have to recheck that, but the round hole to the square hole is a dead give away.
From the round hole to the square on the big block is smaller.
I would say that yours is a 74 727 SB trans from the pictures.
fratzog lover
Well-Known Member
Krazykuda, what is the square hole for?
Treblig
Well-Known Member
After one of the members posted about the location of the starter I've been surfing the net and found this pic. Not knowing any better I would guess that mine is a BB. BUt I am far from an expert/???
The one I originally posted pics of has the starter very close to the horizontal even with the input shaft.
Treblig
It may be for manufacturing/machining. I have no idea. :banghead:
Treblig
Well-Known Member
That "NAILED IT", it's big block!! Great, now I'll just go pick it up.....but one more thing, I've read about certain 727s that come in motor homes that require a special yoke and it won't work on a car very well. How do I know it's not one of those???
Treblig
skep419
5.9 Magnum 4 speed afficionado
Great info. It shall be stored in my brain in the Mopar Awesome Info section next to never buy a used valve body from ebay.
Treblig
Well-Known Member
Yes!! The small block has that small curve on the lower driver's side ("Dubob") even if the insp cover bolts are not clear in my pics. Mine definitely does not have that small curve. In the original pics I took on my camera you can see the 4 bolt holes as well even though you can't really see them clearly in the pics I posted (two of the bolts are still installed in the bell housing on the passenger's side if you look closely).
I'm still wondering how to determine that it's a car trans as opposed to a motor home trans??? I plan to call the guy and get the stampings off the driver's front rail on the tranny.
Treblig
No need for all the stupid hooha. Very simple. A small block trans has only TWO dust shield mounting holes, a big block trans has FOUR. Kaboom.
The motor home transmissions I've seen have a very short output shaft and tail housing. The ones I've had actually have a drum brake installed on the tail shaft for emergency brake. Very obvious. You can convert a motor home to use by changing the output shaft and housing. The one you're looking at does not look like a motor home.
http://www.forabodiesonly.com/mopar/showthread.php?t=228120
See the diagram I posted in post #2. It gives some dimensions from a performance book I have.
This is the motor home style I am familiar with. There may be others
http://www.forabodiesonly.com/mopar/showthread.php?t=57836
http://www.forabodiesonly.com/mopar/showthread.php?t=228120
See the diagram I posted in post #2. It gives some dimensions from a performance book I have.
This is the motor home style I am familiar with. There may be others
http://www.forabodiesonly.com/mopar/showthread.php?t=57836
Treblig
Well-Known Member
Thanks Dubob, Great info!! The funny thing is that this guy had that pallet with three transmissions on it for sale on craigslist. He wanted $150 for the whole pallet. After close inspection of the tranny housing I was able to determine that he had one 2004R which I had been seeking for a back up (I recently installed a 2004R in my "69 Barracuda) and the second trans looked like a mopar. So I went over and bought the 2004R for $27 (that's a killer price). I took some pics of the 727 and the other trans. As it turns out the guys needs to get rid of the whole thing (pallet of transmissions) and will basically sell each tranny for $25-$30. The other trans (seen on the pallet) looks like a heavy duty one but I don't know what it fits. I hate to pass them up!! I brought the 2004R home with me and posted the pics here to get more info on what I left behind.
The third trans does have a bell housing that separates and you can see the casting numbers in the last pic.
thanks,
Treblig
The transmission above is a Ford transmission. It appears to have a cast iron case which would make it an FMX. They are very formidable transmissions about on par with the 727.
Treblig
Well-Known Member
Thanks RRR, I looked it up after you posted "FMX". Don't have no need for a FEORD transmission even if is only $25. But that 727 BB tranny could be resold for a $100 I imagine??
treblig
fishy68
Tyr Fryr's Inc.
$100 is pushing it by the looks of it. I wouldn't pay more than $50 myself cause it just looks like a crusty parts trans. The only thing that might make it more valuable is if it was from a 440 six pack or hemi car. You'd have to look on the drivers side right above the pan rail and get the #'s off to verify what it's really out of.
Like RRR said the easiest way to identify a SB from a BB trans. is the big block trans. has four 1/4" bolts right at the bottom to hold the dust cover on and a SB only has two 1/4" bolts going through the dust cover. The dust cover on a BB also comes off without removing the starter. A SB requires removing the starter to get the dust cover off.
fishy68
Tyr Fryr's Inc.
Good eye
pishta
I know I'm right....
Never had luck with an FMX, slush box with the weirdest valve body you ever seen, looks like something out of an air conditioner.....
Mrmopartech
Well-Known Member
Sent you a email about the tranny ID,mrmopartech
There are some 8-10 ways to ID a tranny,MMT
There are some 8-10 ways to ID a tranny,MMT
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