• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

big block and small block 727 difference?

thequickster

Well-Known Member
Local time
10:43 PM
Joined
Apr 23, 2015
Messages
106
Reaction score
27
Location
Texas U.S.A
this is probably a dumb question but im a novice to this stuff, but is there a such thing as a big block 727 trans and a small block 727. and if there is what is the difference, i have a 67 coronet 318 727 trans and was looking into a big block purchase and wanted to know if my current transmission would work.
Any help is greatly appreciated Thanks -thequickster
 

Attachments

  • IMG_3287.jpg
    IMG_3287.jpg
    61.3 KB · Views: 2,122
No, that's not a dumb question.... there's are two different versions & they're different where it bolts up to the engine. I think they're called 727A (small block) & 727B (big block). I think most of the small block ones were behind 340's and I think the 360's had a A-999 or something like that (?) and the 318's and 6's used 904's. The big block 727's are much easier to find.
 
Besides the difference of the bellhousing, clutchs and carriers are different.
 
good 67 you have there...nice straight body. I looked EVERY WHeRE for one of those...before my 68
 
If you are looking for a 727 also be aware of the later ones "lock up" converters. The "regular" 727 has splines all the way to the end of the front shaft. The "lock up" version has a smooth area looks just like a 4 speed pilot shaft.

Depending on the year, the guts will interchange out of the different cases, as noted above, some are better than others. Highly recommend you spend the bucks on the book by Munroe

http://www.amazon.com/Torqueflite-A-727-Transmission-Handbook-HP1399/dp/1557883998
 
Smallblock A727 is 7 3/4 inches between top center mounting holes A727 bigblock is 6 7/16 between same bolts. Ditto 440roadrunner, get the HP book #1399.
 
Thanks for all the advice I'm just a young punk workin on my car and love learning this stuff, I'll be on the lookout for a big block trans now. thanks for all the help

- - - Updated - - -

Thanks it's my 1st car
 
The small block 727 was used on the old 318 Poly, and 66-67 318 B body(273-318). it basically was the standard 6 pinion(forward and reverse). The 340 was different again, as was the Taxi and police 727. The 383 had the six, seven, and eight pinion. The 383 two barrel was the basic, the 383 four barrel was seven(Exclude roadrunner and Superbee) the 440(full size non HP) was seven,(4-3) and the R/T, Roadrunner/ Superbee was eight.(4-4) The hemi was eight, but modified further. So, there were a variety of 727 transmissions.

I recommend buying an original 440 transmission, as they are available, and can perform with the best, with some modification. And they aren't too much money. Look at the part numbers on the case, and it will tell you which it is.
 
I need a shift shaft for a big block 727 transmission and have found a small block 727 transmission, are the shift shafts the same?
 
Auto Transport Service
Back
Top