Joined: Fri Aug 05 2011, 08:06PM
Location: Brisbane Australia
Posts: 132
Spending wayyy too much time deciding what to do to my 727, I am trying to choose between a transtar kit from northern auto with raybestos clutches or a kit from TSR with alto reds.
The car and usage - 68 fury 2DHT 383 2bbl currently, plan to rebuild (within 12 months -provided the economy and my shop dosent tank), high comp, 268(ish) cam, 4bbl and some alloy heads - aprox 380-400hp?. Have a 2.76 and a 3.23 center to swap between. Will be driven (moderately) tamely most of the time with a few blasts down the 1/4 - Sadly we have particularly evil anti road hooligan laws, on your 3rd high speed or smoking tyres or "racing" offense (including speeding up to go through a traffic light) they crush your car, not high on my list of desirable modifications.....
Have a FSM, Carl Munroes' book, youtube vids and most of a plan of attack
On top of the RB kit, will be going a pump rotor, rear bearing, stage 2 transgo kit, deep pan, 3.8 lever, HD band strut and maybe a billet rear servo & retainer kit (not 100% sold on requiring that)
Sprag - No im not putting a bolt in one in, they were intended as a repair item originally, but are put in most hp trans as "insurance". My take on it is i would rather have it spin in the case an need repairing with a bolt in one vs the rock and hard place explosion. With responsible driving and maintenance the issue should never come up. On a side note a few vendors seem to be drilling 2nd hand ones, buyers beware, look for the word new in the description, many of them use the word modified...
Am leaning towards the TSR kit atm - $140 dearer, but comes with red/kolene's, a solid red band and has a rear band inc plus rollers for the sprag
However, the good old interweb assures me that the transtar kit will be fine for what im going to throw at it
As a 2bbl 383, when i pull it apart i am expecting a 3 clutch drum (same as a smallblock) - now many years ago a trans guy told me that you only run as many clutches as you actually need as each one costs friction/horsepower. Back to today and every one seems hellbent on cramming 5 or 6 clutches in
So my Q's are: transtar or dearer kit? and has anyone tried running only 3 clutches with good frictions on around 400hp?
The last thing you want to do is do a tranny cheap.if you intend to that,please don,t ask any more advise from us,as this will be wasting our and your time.Either do the tranny the right way or nothing at all.If you intend to do it right,build a hemi version of the 727,5 sets of clutches and plates in each drum,proper levers and servos,shift kit,deep pan,bands,and a higher stall convertor.This and a big ass oil cooler that does not run through the rad,will get you the best results and life time,pleasure.mrmopartech
Joined: Fri Aug 05 2011, 08:06PM
Location: Brisbane Australia
Posts: 132
Your very right on the not being cheap bit, I re read the post yesterday and thought "what the hell are you thinking" (i'll blame the bourbon) the extra $$ will keep me from stressing about stuff failing cause it was cheaper - so another week or two at the salt mines
With any recommendations, please bear in mind location - we have the "Australia tax" anything I get costs 10% more due to exchange rate and then has to be shipped to CA and then over here at $20 plus $4-5 a pound - Anything more than $1k and add another 15% for duties n taxes - Sadly that still works out cheaper on most things than buying it here. Also there is pretty much no where local that I can pop down and buy any go fast bits, "standard" parts can be very hit n miss too as the number local cars that came with a 727 would be in the 10's of thousands not the millions(?) like over there. There wouldnt be a huge number that came with a big block either, low 1000's. So while i can go and buy a core (barely), used loose parts are extremely rare
TC - Have a local co who do converters with torrington bearings that i was going to go with, somewhere around the $500 mark. The stock 1800 would go up to about 2k with the extra torque, want to try make it work with both ratio's and not be under the stall at highway speeds, hard but ill figure it out, there would only be a few tenths in it going much bigger any way
Trans cooler, yes yes yes - not so sure about not running it through the radiator though (after the cooler), trans fluid has a definite working temp range and getting it cooler than that is meant to be detrimental. May be a moot point - mines leaking on a couple of cores at the top, will pull it soon and see what the local rad shop has to say. If its too much i will probably go a ally rad, but currently cant get (a cheap*) one locally with a trans cooler
Was expecting to cop flack about the sprag - agree or disagree MrMT?
Clutches/steels - Im thinking that the thicker steels would be better for heat dissipation, but to fit the thick ones with 5 frictions, i will prob have to get the ring groove cut further out and a thinner clutch/snap ring - may not be possible, thinner steels will do if i cant - Any one managed to do this?
I agree with the previous post on not to use sub-engineered parts.
In what parts to use ( or from whom ) --- look at what was originally used for any and all Model 727 Transmission's. They where placed with 1 bbl 225 cubed six's in Dodge Trucks ( aka Load-flite's ) to Motor Homes that have a front area as big as a garage door. In Car Division's it was The Imperial Division only with a 440 and a plus two ton rolling weight down to what you have.
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
I will add one small comment. You're looking at swapping between a 2.76 and a 3.23 for what reason? Street versus strip? Highway versus city driving?
Those ratios are pretty close together. My guess is that you'll quickly conclude that the fuel economy difference between them isn't worth the hassle of swapping them, and you'll just leave the 3.23's in all the time.
Joined: Thu Mar 22 2007, 08:13AM
Location: In the workshop
Posts: 1063
Alchemi wrote ...
Trans cooler, yes yes yes - not so sure about not running it through the radiator though (after the cooler), trans fluid has a definite working temp range and getting it cooler than that is meant to be detrimental.
What I would normally d is run the line into the transmission cooler part of the radiator, then into a bypass thermostat, then into the auxiliary cooler. Thats the best way to get the trans fluid to the correct temp, and keep it there.
While this part is now on "How To Route/ Use A Transmission Cooler" - I'll say there must be a reason that every factory used unit in the world has the hot fluid going from the Transmission to The Tank below The Radiator --- then to The Auxiliary Transmission Cooler --- before the cooled fluid returns to The Transmission. Not a one of them by-passes the tank at the bottom of The Radiator.
The C-Body era Factory's Auxiliary Transmission Cooler is as wide and tall as The Radiator. It is also placed in-front of The A/C Radiator if the vehicle is optioned with A/C. Look in the first ten pages of Group 7/ Cooling in The Factory Service Manuals to see how MoPar's are done.
**** All C-Body's sold to the general public with Auxiliary Transmission Cooler's was ones that had The Factory Towing Package or It was a Special Requested Option. ****
Now let us move on to wanting A High Compression ( when the starting point was 10:1 in 1968 ).
Joined: Fri Aug 05 2011, 08:06PM
Location: Brisbane Australia
Posts: 132
Kind of comes down to the question of how hot that bottom tank is dosent it? from memory 175 is the magic number for trans fluid, but most ppl seem to like a 180 thermostat, although in theory a hotter one is better for combustion temps. The bottom 1/3 of the rad dosent get direct airflow, but the fan would be still be pulling some air through there, potentially not at speed though. Might have to look into an anemometer and a temp gauge to answer that one
I like Joes idea of a thermostat controlled mixer - something like you would put on a hot water system so the water dosent come out scalding hot - hmm could combine that with an accusump sort of setup... hmmmmm
Diff - yeah was thinking that, will have play with some numbers, but a 3.55 or 3.9 no doubt would be better, my original chunk is a 742 with the 2.76 and i picked up a 489 with the 3.23 recently for only $200 and grabbed the axles for another $50 - a bargain for oz
I'll leave the High compression motor to another post, when im closer to building
Joined: Thu Oct 13 2005, 08:23PM
Location: Beautiful Down Town Roebuck Ontario
Posts: 227
Your right about the sprag. The so called bolt in one is really no better than the stock one BUT the Super Sprag bolt in unit has 2 more elements in it IIRC so there is less room to "roll" them over. It sounds like for your intended purpose the stock one will do. Lots of people have gone stupid fast with stock ones for years. Keep in mind a stock 383 has the ability to spin up tight enough to explode the front drum should the sprag fail for whatever reason.
This guy has a solid gold reputation and can set you up with what ever you need and won't sell you something you don't need.
Does it get cold as in snow on the ground cold where you live? If not or the car will never see time in those kind of temps, the thru the rad cooler first or not debate is IMHO a moot point. The trans temp will get to acceptable levels in short order.
Rear gear? Just put the 3.23 in it and be done. This is assuming a 28" tall tire. 275/60/15 or 235/70/15.
3.91's are good at the track and a hoot around town but they get old real fast at freeway speeds. 3.23's are a pretty decent compromise. Short enough to get that big boat out of the water in a respectable manner and tall enough to run 70 MPH without spinning the wee out of it.
Joined: Sat Apr 29 2006, 05:11PM
Location: Cincy
Posts: 269
In my race car I run the super sprag. In my daughter's 400 hp 4000 lb street/strip car I run a regular bolt in sprag. If I were to do it again, I will put a super sprag in it also. The sprag is nothing to mess with - I have personally witnessed a tranny destruct because of them, and the car was barely off idle. It was not a super high hp car.
I will also never run a 727 with a stock cast drum. $600 is a cheap investment in y opinion for a steel drum. And I can say my A&A tranny with a steel drum is a tad faster than my Dymanic tranny with an aluminum drum.
5 clutches for sure.
My buddy built my daughter's tranny with the steel drum, bolt in sprag and 5 clutches for around $1200. He charges $150 in labor to put a 727 together.