I was planning on using a 1970 rebuilt truck 727 behind the 1965 273 I just finished, if I end up dropping it in a 1961 D100 shorty. I read a post here recently saying that the early 273 will not take a later model auto trans. Any help here? Chris.
auto trans for 1965 273
- Thread starter txas2step
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Early (64-69) 273 is a small block and any small block will bolt to any 62-later 727/904 with the small block bellhousing. Shifter provision will vary depending on the transmissions- rod, cable, etc
The 273 has a smaller diameter register/counter bore in the crank. A special custom torque convertor solves that. You wouldn't like the 727 behind a 273 anyway. The 904 has a much more compatible lower gear ratio. 727 just doesn't transfer the torque to the pavement as well plus the stock 273 aint loaded with low end torque.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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What about the TC register?
OOPs Redfish beat me to it
The pick-ups had 727s partly on account of the Looooog driveshafts required with 904s; but you said shorty....so........ Since you already have it.......and you're gonna need a adapter TC anyway, I wouldn't be scared to use it.
But if you go shopping for a 904, try to get a 71 or newer; By 1971 most of the 904 bugs were solved and they have the part-throttle kick-down feature which I really like. Since you'll need a custom TC for this too, then this is a great time to consider a stall increase. And if you have a choice; the 71 Demon 904, I have found to be a fabulously calibrated unit.
OOPs Redfish beat me to it
The pick-ups had 727s partly on account of the Looooog driveshafts required with 904s; but you said shorty....so........ Since you already have it.......and you're gonna need a adapter TC anyway, I wouldn't be scared to use it.
But if you go shopping for a 904, try to get a 71 or newer; By 1971 most of the 904 bugs were solved and they have the part-throttle kick-down feature which I really like. Since you'll need a custom TC for this too, then this is a great time to consider a stall increase. And if you have a choice; the 71 Demon 904, I have found to be a fabulously calibrated unit.
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And you will need a converter that has the correct sized hub to match up with the early crank. Man you other guys are quick!
Plus it's bigger, heavier, and takes more power to drive.
Depending on what crank was installed - small register up through 67 cranks unless previously open up.
Good morning Chris
I believe someone with more expertise should reply soon but I think the issue you will need to address is the converter snout that registers in the crankshaft. I believe the 273 has a smaller diameter. You will need a special converter I believe. Maybe a search on here will gather more info. Good luck
/6 tranny won't bolt to a v8
slantsixdan
=..=
True and correct.
The 727 and 904 gear ratios are the same:
2.45:1 (first)
1.45:1 (second)
1.00:1 (third).
Except the '80-up wide-ratio gearset for the A904/998/999 is 2.74/1.55/1.00, but that doesn't enter into this topic.
(and as others have noted, the 727 is unnecessarily heavy and will consume more power than a 904, and the truck trans is way too big to fit in an A-body without major surgery.)
slantsixdan
=..=
There is nothing such as an early '90s 904. Just what is this trans from?
pishta
I know I'm right....
T flite paddy has a bushing to put a early convertor into a later crank but nothing short of a crank transplant will get a late convertor into an early V8 motor.
Or early slant motor
BillGrissom
Well-Known Member
That isn't the only option. As others said, one can get a custom-made torque converter w/ a smaller snout. I recall posts where people listed a manufacturer who made that. People have wondered if there is enough meat on a later TC to machine the snout down to fit, and perhaps that is how they fabb'ed it. Another option people have mentioned is to swap both the torque converter and front components (input shaft, pump, fwd drum) into a later transmission. The advantage is probably that those parts are small enough to ship affordably. Of course, if you can find a pre-1968 small-block transmission locally, that would be ideal. 1964 & 65 tranny's are cable-shift and have a fixed output flange (instead of sliding yoke), which might be harder to retrofit in a truck, so a 1966-67 tranny might be best.
Yes, I want to stay away from the early cable trans..( w/flanged OP). Guess I'll look at locating a 66-67 set up(trans/TC) locally or see about a source for a modified snout. Good info. nothing easy about this one. LOL.
So a good while back there was a member with the same torque convertor register issue in his slant 6 application. He found the special torque convertor at a reasonable cost. I should have kept a link.
If you do buy a 68 or later 904, try Fatsco Transmission. They should have all the help you need to make it easy.
Call Precision: Precision of New Hampton | Torque Converters, Transmission
pishta
I know I'm right....
Bill, I parsed my words very carefully saying a late converter (not a custom converter) wont fit an early crank. Any idea what the small snout conversion on a big nose converter would cost? I thought I had one at one time and was rather excited but found it was not the adaptive spline count/snout size.
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