3.91 gears for a 741 case?

[thequickster]

Hello, I have a 741 case in my 67 Coronet and I’m looking for a new ring and pinion gear . I have been looking for a 3.91 ( or is it 3.90? ) gear set and the closest I can find is a 3.73 . I was wondering if any manufacturer makes the 3.91 set for a 741 case or should I just go with the 3.73. I have already called summit and they only carry the 3.73. The car has a 440 30 over with 440 source aluminum heads and an eddy performer intake topped by a Holley 750, with the 727 trans .
I’ve looked into getting a 742 case but I would like to stick with the 741.

Any help is appreciated, thank you

-TheQuickster

 

[Joe66satellite]

Hello, I have a 741 case in my 67 Coronet and I’m looking for a new ring and pinion gear . I have been looking for a 3.91 ( or is it 3.90? ) gear set and the closest I can find is a 3.73 . I was wondering if any manufacturer makes the 3.91 set for a 741 case or should I just go with the 3.73. I have already called summit and they only carry the 3.73. The car has a 440 30 over with 440 source aluminum heads and an eddy performer intake topped by a Holley 750, with the 727 trans .
I’ve looked into getting a 742 case but I would like to stick with the 741.

Any help is appreciated, thank you

-TheQuickster

I have a very similar car to yours quickster 66 Plymouth satellite weather 440 with all the same goodies ,it has a 391 with a Yukon case I find those gears to be too short for City driving I have had some issues with the upshift on my freshly rebuilt art car transmission I have everything right with the lokar kickdown cable it just seems to me it comes out of first too soon and into third too late just under normal City driving conditions with it in Drive, I expected to come out of first pretty quick with such a short gear I'm going to experiment with a little more pull on the kickdown cable I followed a lot of instructions on this wonderful website and I think I've got it pretty close, I know I didn't quite answer your question other than mines a Yukon and it was a 10in drum brake car so it was probably the same rear end as yours and my PO upgraded to the Yukon case with 391,what gear ratio are you coming from?

 

[thequickster]

I have a very similar car to yours quickster 66 Plymouth satellite weather 440 with all the same goodies ,it has a 391 with a Yukon case I find those gears to be too short for City driving I have had some issues with the upshift on my freshly rebuilt art car transmission I have everything right with the lokar kickdown cable it just seems to me it comes out of first too soon and into third too late just under normal City driving conditions with it in Drive, I expected to come out of first pretty quick with such a short gear I'm going to experiment with a little more pull on the kickdown cable I followed a lot of instructions on this wonderful website and I think I've got it pretty close, I know I didn't quite answer your question other than mines a Yukon and it was a 10in drum brake car so it was probably the same rear end as yours and my PO upgraded to the Yukon case with 391,what gear ratio are you coming from?

I also have the lokar cable on mine as well as the 10 inch drums all around, I have no idea what the ratio is currently but I’m sure it is highway gears ( possibly 2.93s) , I have looked at a lot of sights and only found the 3.73 set available. The car will be mostly in town driver so I’m starting to lean towards the 3.73. I just checked the Yukon website and didn’t see the 3.91 ring and pinion alone. Very interesting hearing from someone with a similar set up , thanks for the info.

-TheQuickster

 

[wyrmrider]

you can lighten the governor to make it shift later

late governor is more adjustable

IMHO Art Carr used to be hard on parts
and NO TYPE F or trick **** if Carr is still recommending

 

[Mysons68 dart]

I have been looking for some 3.73 gears and after posting my build on FABO and asking for gear suggestions it was recommended i go with 4.10s so i looked all over for 4.10s and 3.91s but didnt find any. Im gona call dr diff tomorrow and ask cass about it.

 

[john-9]

Hello, I have a 741 case in my 67 Coronet and I’m looking for a new ring and pinion gear . I have been looking for a 3.91 ( or is it 3.90? ) gear set and the closest I can find is a 3.73 . I was wondering if any manufacturer makes the 3.91 set for a 741 case or should I just go with the 3.73. I have already called summit and they only carry the 3.73. The car has a 440 30 over with 440 source aluminum heads and an eddy performer intake topped by a Holley 750, with the 727 trans .
I’ve looked into getting a 742 case but I would like to stick with the 741.

Any help is appreciated, thank you

-TheQuickster

the street gear ratio choices for any 8-3/4 are starting to be very limited as you have found out -- US Gear completely dropped their 742 gear sets and only have gear sets for the 489 cases and the other manufacturers are following suit . 741 case -- 2 sets ,,, 742 -- 5 sets ,,, 489 -- 7 sets ,, of gear ratios to choose from
even the Dana 60 has very limited selection of gear ratios.
this is probably due to a very limited market as 8-3/4 use is becoming a collector car only market -- not so much use in auto racing arena.
you see this in the price being charged for 8-3/4 ring and pinions compared to the price of 9 inch Ford gear sets.

anyone that is serious about racing would move up to a 9 inch Ford due to the strength , selection of gear ratios and aftermarket support.

 

[wyrmrider]

Alas it is so
Looking for a 3.54 for a Dana 60 in a chevy PU with a Cat Diesel

 

[thequickster]

Yes every aftermarket sight I have found is limited to 3.55s and 3.73s for the 741 case. And I’m not going to be serious about racing my car, just looking to make my daily more interesting since we swapped the 318 for a 440. Looks like the 3.73 will be the way to go now, if I every get the desire to really beat on it at a track, I will probably find another case and build it with 4.10s since I have a spool laying around.

Thanks - TheQuickster

 

[Joe66satellite]

you can lighten the governor to make it shift later

late governor is more adjustable

IMHO Art Carr used to be hard on parts
and NO TYPE F or trick **** if Carr is still recommending

Could you be more specific please I'd like to know that this was a good investment but it's from the previous owner so it's hit-or-miss for me it seems that he bought some high performance transmission fluid that's in it please tell me more about what you know about the art carr brand build

 

[Mysons68 dart]

Yes every aftermarket sight I have found is limited to 3.55s and 3.73s for the 741 case. And I’m not going to be serious about racing my car, just looking to make my daily more interesting since we swapped the 318 for a 440. Looks like the 3.73 will be the way to go now, if I every get the desire to really beat on it at a track, I will probably find another case and build it with 4.10s since I have a spool laying around.

Thanks - TheQuickster

I talked to Cass This morning and like everybody is saying they don't make anything aftermarket past A 373 So for me it looks like 373s or 355s are where it's at and probably look for a 489 case with 410s when I want to go to the track

 

[wyrmrider]

it's most likely an ok investment
I have not dealt with Carr since the late 60's
his valve bodies would chirp the tires- shifted hard and eventually broke parts I had one of his C4 trans in my xke Jag starting with a Shelby 350gt valve body and modifying from there
The late Gil Younger at Transgo always held that you could not win if you broke
and also was always down on Type F which can cause lining failure he said not to use Type F in anything that did not specifically specify it

Dave and the crew maintain this philosophy
actually TF will work on most anything like motor oil to get you home
I was in on the very first TFOD transgo shift kit tranny development back in the early 90's and can attest to the amount of R&D not copy cat
They have updated the kit for the electronic and later versions
check out their new TF separator plates cures things that cannot be cured with just a shift kit- like anytime back to second with the OD trans- like mine