The Dodge Challenger Message Board

I'm looking at buying a 73 challenger, and according to the seller, the 340 AND 904 auto tranny are original. I thought the 904 was reserved for the small blocks, but werid things did happen. Does anybody know if this is possible? Thanx, jon

a 340 IS a small block . . .

As far as I know a 340 is always backed up by a 727 transmission, not a 904. But I could be wrong. One thing I know for sure is that I have originally a 340 w/ 727 in my 72 Challenger.

To be sure if the car you're looking for came with the 340 w/ 904 check the fender tag, or the #'s.

Hope this helps something!

The 340 always had the 727 trans. The seller does not know s**t from shoe polish.

Have a look at the trans oil pan on the passenger side of the car. On the 904 trans the side of the oil pan is straight. On the 727 there ia a bulge in the pan rail where the dipstick tube is.

If it has a 904 fitted either walk away from it or offer a price for the car that reflects the cost of putting it right.

Have a look at the engine as well just in case it is a 318. There is a i.d. pad right under the drivers side head gasket on the front of the engine. It will have one or two letters and then the engine size. Small blocks came in 318, 340 and 360 sizes.

Before handing over money get a pencil rubbing of the fender tag which is on the drivers side inner fender. Post the numbers here as they look on the tag and we will tell you what it should and should not have.

No tag = low price in my book.
Good luck.

My old Challenger had a 360 on a 904 (originally a 318 2bbl so it was probably the original box)

With spirited driving the 904 was soon fried & I had to fit a 727.

When pricing you need to take the following into account:
727 with a small block bell housing & dipstick/tube & torque converter
changing the prop shaft as the 727 is about 4" longer than the 904
Upgrading the u/j's, slip yoke & yoke on back axle to heavy duty
plus countless other odds & ends you did not bargain for.

But if it is a 318 the conversion does not matter & you need to use your own best judgement as to how you deal with the guy if he's trying to con you.

Actually, I think you could get a 360 with a 904. But NOT in a Challenger. Challenger 360s were all 4-speed or 727 trans.

If you are planning to do the 440/4-speed swap, you might save yourself some time and maybe a few bucks and find what you want. Maybe different if you have the parts to swap and the price is right. If it is a 318 car, then a 440 will increase the value, not much change for a 340/360 if original. That may change in the future, so keep the (if original) 340 block. Lots of people have done the big block swap to the later Challengers, so if you want a BB car finding one should be easy.
Tedd

I have decodeing my fender tag.
1973 challenger rallye.
restoration guide by Paul Herd.

My tag shows 340 C.I. with trans. code D34
which is A904.

Here are the transmission codes for 72 through 74 that are listed in the White book for those years:

D13 - 3-speed manual trans, floor shift
D14 - 3-speed manual trans, column shift
D15 - 3-speed manual trans, column shift HD
D21 - 4-speed manual trans, floor shift A833
D31 - A904 3-speed automatic trans
D32 - A727 3-speed automatic trans
D34 - Standard duty automatic trans
D35 - Heavy duty automatic trans
D36 - A727 3-speed automatic trans
D41 - HD clutch, 9 1/2" Dia.

Please draw your own conclusions, but I think your D34 code may or may not mean you have a 904 transmission. A visual check of your transmission to as described by Dave might be needed to verify its type as Mr. Herd has been known to err on details.

That will be great if you can check that Jerry.

The book "Mopar chassis/Carroll Shelby's speed secrets" says that the A-904 was used in the
6 cylinder, 273 and 318.
(It also says that A-727 was used in the 340, 360, 383, 400, 440 and Hemi 1962-1974).
I hope this helps.

COME ON JERRY! SHOW US WHAT YOU'VE GOT!

Just to help Jerry i.d. his trans here are two photos.

This is the right side of a 904 trans. Note the straight edge to the oil pan rail.



Here is a 727 viewed from above. See the pan rail is not straight? It has a bulge near the filler tube.

Thanks for the info. I have also been able
to track some info. on my car.the 727 was removed
and replaced with a 904. I have also found a 727
working for $150.00,but will rebuild before installing.
Jerry

Ah! Thanks for that Jerry.

Jerry; Will you do the re-build?

as dave mentioned , the d34 code does not specifically mean a 904 , when I first bought my car someone said that to me , but my car had a 727 in it so I assumed it wasn't a #'s matching trans , however the 727 is #'s matching for the car on the 727 in my car for instance , on the "passenger side" of the trans , on the bell housing basically just above the "bulge" in the above photo , the last 8 digits of the vin# are stamped on a flat spot. thats how you'll know if the #'s match. as for wether or not the 904 ever came behind 340's or 360's in challengers , I couldn't tell ya so I'd be inclined to believe the others :>) However , if it did , you would be assured it would have only been behind one of the detuned 72 or 73 cars and not in a 70 or 71