Okay here we go again.  I have a 73 small block 727.  I also have a 66 Big Block 727.  the 66 I am told has 19 teeth on the front pump spline.  Will the front pump from the 73 work on the 66 727.  By doing this I am trying to make the front pump on the 66 a 24 spline so that I can get a Stall convertor for more reasonable price then 525.00 that I was quoted for the 19 spline front pump.  Is my theory correct will this work?  

Gipper,

I know that their is a difference between the early and later 727's but I don't know if it affects the pump interchangeability or not. Did you count the splines to make sure it only had 19, I have a 78 727 setting in my shop put I don't know if it's any good or what it would cost to ship it to you.

check out the rebuild kit listings at a local shop or on the net. I believe they are the same for both transmissions. Also you could pull both pumps and compare gaskets and inlet-outlet passages.

do you know if there is any difference between the torque convertor for a small block and a big block?  

I believe that 727's share the same converter but there are two different bolt circles for flex plate attachment. 10" is most common. but there is also an 11-1/8" version. so if you have a flex plate make sure the holes in the converter match up. another difference was either 6 or 8 bolts for the crank. also you need to determine if yours is a lockup or non-lockup, and be sure that the new converter is balanced the same as the old one (internal/external). I have a SB and BB 727 on my garage floor, so I'll check the spline counts for you and reply tomorrow. Check out coan's website, lots of good info there.

later

steve

first of all while ai still remember it what is coan's website?  I really appreciate all the info and advice you have given me on this.  I need sit down and take a look at what I actually have and what  would be the best for me to do at this point I guess.  The torque convertor from the BB has be drilled and a drain plug put in it. I hear that is a good thing and that it was not a stock thing so I am wondering if someone has already done some work to this one.  My SB 727 is still hooked to the block covered on a stand in my side yard so I will have to seperate the two to take a look at it.  Anyway, thanks again.  

OK...It's been awhile since I rebuilt a 727 and now that I looked at the two I have in my garage I remembered some other details. The splines that you refer to are the input shaft splines and the input shaft is not part of the front pump. both of mine (SB & BB) are 24 splines and have the same casting number. the other splines (27 of them) are on the ground sleeve and it is bolted to the front pump. So..just changing the front pump won't solve your problem, you will need to swap the input shafts which requires partial dissassembly of the trans. I believe you can get it out by removing the front pump assembly (it has two threaded holes 180 apart for slide hammers), the valve body, and the kickdown servo then loosening the kickdown band and pulling out the front clutch assembly. You may want to have someone with trans experience help you with this!

another option would be to send in your old converter and have it loosened up and converted to 24 splines. this will depend on how much stall you must have.

for Coan: just type in "Coan transmission" in your search window. that should get you there.

good luck!

steve