Best year(s) 904 for a street/strip car?

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motorpirate

serial mopar owner
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Another thing on the back burner, After I get the rear diff sorted out (eBay used 3.55's are whiney junk!! replacing this week with a virgin set) we are going to start the Magnum swap.
At first this will be on the '66 904 original to the car (18 spline converter) which works fine, but if i am going to go into it to better suit the Magnum set up I think it makes sense to build a 27 spline trans to have a better choice of convertors, etc.
Plus that will leave me with a fine running 273 2bbl/904 combo to put in Dads '48 dodge?

So, what year/years would be the best to look for? Car is a'66 Barracuda weighs 3400.
3.55 rear and will be driven to the track about 40 min away on the interstate at 65/70 mph.
Will NOT be a manual valve body.
If i know what to look for, while Dany and I are busy with the motor, I can keep my ear to the ground, I know I can kick up a good core to go through, if I know what year range to look for.

Again, thanks for all your help guys!!
 
My experience has been with the latter years 70+ but only to simplify the torque converter debacle.

Jake
 
I believe it is the 72 oe 73 and newer is what you want...one of the servos changed..
 
The 66-67 904 does have a front and rear pump, if that makes any difference. And the converter debacle is easily overcome with an annular ring.
 
on the driver side just on the pan rail...there is a number stamped that starts with a PKxxxxxxxx then xxxxx
 
71+ are the better ones IIRC. There is a difference on the outer case where the Servo is located as Tony mentioned.
 
I know there were 904’s that came with a 5 clutch drum. I don’t know the specific year, but I think you can build any 904 to survive behind a pretty serious motor. I know of a 5 clutch 904 in small block demon that runs 11.70’s and it’s not even working hard
 
Vin# pad will also tell year.
I run a 84 lockup 5 clutch low gear set from a Diplomat. TF2 shift kit, lockup circuit plugged, Turbo Action 10" S800 26 spline 3200 tight converter, 3.91 gear. 340 375-400 real world hp, Launch car at 2k 1.65 60', 11.77 best so far in ok air. I pulled the tranny after 400 passes and it looked good so it when back in with new seals only. Lockup input shaft is plenty strong for what I'm doing street/strip drive 100 miles round trip to the track.
 
mderoy340 said:
Vin# pad will also tell year.
I run a 84 lockup 5 clutch low gear set from a Diplomat. TF2 shift kit, lockup circuit plugged, Turbo Action 10" S800 26 spline 3200 tight converter, 3.91 gear. 340 375-400 real world hp, Launch car at 2k 1.65 60', 11.77 best so far in ok air. I pulled the tranny after 400 passes and it looked good so it when back in with new seals only. Lockup input shaft is plenty strong for what I'm doing street/strip drive 100 miles round trip to the track.
Click to expand...
So sounds like I'm looking for a Volare/Diplomat/5th Ave trans..
 
the 4 disc drums can be outfitted with 5 disc....just have to use the thin .068 clutch disc instead of the 086 thickness....I got 4 904 like that......
 
cosgig said:
The 66-67 904 does have a front and rear pump, if that makes any difference. And the converter debacle is easily overcome with an annular ring.
Click to expand...
Do tell about this annular ring!
 
rumblefish360 said:
Do tell about this annular ring!
Click to expand...

67 down 904 had a small input shaft, and pilot on the engine end of the converter. This matched the size of the pocket in the end of the crank, for small blocks, and slant sixes. In 1968 the crank pocket, converter pilot, and input shaft got larger. This is why you cannot put a 67 or earlier engine, up to a later trans. You can put a later engine up to the early trans buy using an adapter ring in the end of the crank.
 
Isn't the output a little latger on the 73 up, also?
 
If you mean the output shaft where the front drive shaft yoke slides in.
No. 1966 up all the same. 1965 down, has the flange.
 
Charrlie_S said:
67 down 904 had a small input shaft, and pilot on the engine end of the converter. This matched the size of the pocket in the end of the crank, for small blocks, and slant sixes. In 1968 the crank pocket, converter pilot, and input shaft got larger. This is why you cannot put a 67 or earlier engine, up to a later trans. You can put a later engine up to the early trans buy using an adapter ring in the end of the crank.
Click to expand...
Thanks Charlie. For some reason, I thought it was an adapter ring on the trans to use a later converter.
 
Just a FYI
I used to get my converters built (hard to get them now) with the small pilot, and the large splines. That way I could use the early engine with the late trans. Or use the early trans, by changing the front pump and input shaft, to the late items (they will interchange). Or use the late engine, by using the adapter ring. Gives me more options.
PS: I like to use the pushbutton trans with the late front section parts, with either late or early engines.
 
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