NoAlso on a separate note, I have an extra ball-n-trunion B body trans, would that also have the 3.09 first gear?
NoAlso on a separate note, I have an extra ball-n-trunion B body trans, would that also have the 3.09 first gear?
Yeah, if memory serves, the OD 4-speed goes from 3.09 low to 1.67 second. The direct drive goes from 3.09 to 1.91.FWIW, my A833OD first to second drop is significantly worse than the 1st to 2nd drop with the 3.09:1/1:1 gear set, and I run a low compression 360. And I don't find that I have to rev it to the moon before I reach for second. I just drive it and it feels fine.
For comparison sake, my 360 has rebuilder pistons from about 1991 and they are about 1/8" in the hole. Even with the smaller combustion chambers of the MP R/T heads, I figure I am only 8.5:1. And my cam is a regrind from Bullet with 262/267 or 206/210 @ 0.050. The thing needs more compression and yet it drives fine for me.
BTW
the 3.09 low gear trans, is a completely different gearset. IIRC ONLY the low-gear will swap with a 2.66 box.
??? Unless I'm missing something, a 3.09 low gear would need to mesh with a counter shaft for a 3.09 low gear. A 2.66 counter shaft wouldn't work. So unless the other three gears were the exact same ratios, the other gears from a 2.66 trans likewise wouldn't mesh with a counter shaft for the 3.09 low gear trans. At any rate, my memory is that the entire gear set and countershaft in my later trans case are from my original 65 Barracuda trans.
OK, been a while since I've been in one, or examined how the power is transmitted through the trans, but I vaguely remember that in low gear, the first gear locks onto the counter shaft, goes to the rear down to the most rearward gear on the counter shaft and up into the main shaft. So the first gear can be the same for different low ratios because the rearmost gears on the counter shaft and main shaft are different for the different trannies, giving each trans different low gear ratios with the same number of low gear teeth.Based on the chart in post #20, first gear on the mainshaft is the same as the 2.47 and 2.66 gearset. But 2, 3, input and cluster gear are all different. Maybe that's what he meant?
OK, been a while since I've been in one, or examined how the power is transmitted through the trans, but I vaguely remember that in low gear, the first gear locks onto the counter shaft, goes to the rear down to the most rearward gear on the counter shaft and up into the main shaft. So the first gear can be the same for different low ratios because the rearmost gears on the counter shaft and main shaft are different for the different trannies, giving each trans different low gear ratios with the same number of low gear teeth.
What I call the counter shaft and the chart calls the cluster gear is specific to each transmission. The low gear is interchangeable in several, but just changing that won't change the actual low gear ratio.
Did I figure that right?
Have to say I never knew the same low gear was used in different transmissions with differing low gear ratios.
For first gear selection I use a combination of trans X final = about 10 to 1. So if you want good fuel economy and quiet operation on the hiway, you would choose a taller final drive to keep the RPM down. That then requires a lower first gear.I am convinced, by reading @AJ/FormS experience and explanation, that I would benefit greatly from having a 3.09 1st gear and possibly a 1964 - 1965 gear set of 3.08, 1.92, 1.40, 1.
First off, I have looked at Passon's website and read his book but I am not quite finding what I need or not understanding. I'll list my current specs, the issues, options, and then desired effect.
1973 340 Duster, low compression 340, A-833, 3.21 (8.25). Numbers matching car so believed to be the stock gearing of 2.47, 1.77, 1.34, 1. The engine is a standard bore, stock piston, LD340, with a SFT 224/224 @.050, .470 lift, manifolds soon to be TTi steps.
The car is slow to get off the line and can't crawl. Its starting gear is 7.9 (2.47x3.21). I had mistakenly been thinking mine was a 2.66 1st gear with a 8.5 starter gear. I thought a jump to 3.09 x 3.21 = 9.9 starter gear would be pretty good. Now I know my '73 has a 2.47 1st the difference kinda makes it all that much more, almost, mandatory. 7.9 to a 9.9!
My cam is great. I love it and I'm not blaming the sluggishness on the cam. I believe this change will allow the cam to serve me in it's peak performance. I currently have a 3.21 SG 8.25 rear which is factory equipment BUT I do have a 8.75 housing coming together with a 2.94 Eaton True Trac diff and a core 3rd member for a 3.23. Switching to 2.94 isn't a huge problem for the payoff as I do intend to drive on multi-day cross country trips BUT I will also be able to put the 3.23 together for normal use and be close to my current 3.21 gear.
I would like to do the transmission gearing change ahead of a rear gear change so I will know how 3.2X feels with a 3.09 1st gear.
Is it possible to convert my VIN stamped case and put 3.08, 1.92, 1.40, 1.00 gears in place of the 1973 OEM gears? Is this limited to swapping 1st? What parts? Cluster Gear ?
So, I like a 3.XX gear for my area, farmland, 45-55 mph flat roads (3rd), 65 mph limit on state highways (4th), driving in parking lots slower would be nice. I like the economy of a 3.21 and 2500 rpm. Now, it does suck going 65 (2600rpm) in the 70-75 Interstate traffic. I am looking forward to using a 2.94 and going 70mph (2550 rpm).
No cam swap, no other cases or 5/6 speeds. I want to keep my VIN stamped case. I do also want to swap to the ball and detent side cover during the change out too. I'll be looking at the hydraulic Malwood setup as I have a disability in my clutch foot.
What do I need to do here? Just 1st gear available or can I convert the whole shebang to the early gear set? Let me know if I left anything out.
To the OP, where are you located?
I have 2 or 3 main cases that I would like to sell.
I am in Texas south of DFW.
No I bought my last one from Brewers.Any chance you have an A body big output spline main shaft laying around you’d like to part with??
PM me if you have a critter like that.
I am convinced, by reading @AJ/FormS experience and explanation, that I would benefit greatly from having a 3.09 1st gear and possibly a 1964 - 1965 gear set of 3.08, 1.92, 1.40, 1.
First off, I have looked at Passon's website and read his book but I am not quite finding what I need or not understanding. I'll list my current specs, the issues, options, and then desired effect.
1973 340 Duster, low compression 340, A-833, 3.21 (8.25). Numbers matching car so believed to be the stock gearing of 2.47, 1.77, 1.34, 1. The engine is a standard bore, stock piston, LD340, with a SFT 224/224 @.050, .470 lift, manifolds soon to be TTi steps.
The car is slow to get off the line and can't crawl. Its starting gear is 7.9 (2.47x3.21). I had mistakenly been thinking mine was a 2.66 1st gear with a 8.5 starter gear. I thought a jump to 3.09 x 3.21 = 9.9 starter gear would be pretty good. Now I know my '73 has a 2.47 1st the difference kinda makes it all that much more, almost, mandatory. 7.9 to a 9.9!
My cam is great. I love it and I'm not blaming the sluggishness on the cam. I believe this change will allow the cam to serve me in it's peak performance. I currently have a 3.21 SG 8.25 rear which is factory equipment BUT I do have a 8.75 housing coming together with a 2.94 Eaton True Trac diff and a core 3rd member for a 3.23. Switching to 2.94 isn't a huge problem for the payoff as I do intend to drive on multi-day cross country trips BUT I will also be able to put the 3.23 together for normal use and be close to my current 3.21 gear.
I would like to do the transmission gearing change ahead of a rear gear change so I will know how 3.2X feels with a 3.09 1st gear.
Is it possible to convert my VIN stamped case and put 3.08, 1.92, 1.40, 1.00 gears in place of the 1973 OEM gears? Is this limited to swapping 1st? What parts? Cluster Gear ?
So, I like a 3.XX gear for my area, farmland, 45-55 mph flat roads (3rd), 65 mph limit on state highways (4th), driving in parking lots slower would be nice. I like the economy of a 3.21 and 2500 rpm. Now, it does suck going 65 (2600rpm) in the 70-75 Interstate traffic. I am looking forward to using a 2.94 and going 70mph (2550 rpm).
No cam swap, no other cases or 5/6 speeds. I want to keep my VIN stamped case. I do also want to swap to the ball and detent side cover during the change out too. I'll be looking at the hydraulic Malwood setup as I have a disability in my clutch foot.
What do I need to do here? Just 1st gear available or can I convert the whole shebang to the early gear set? Let me know if I left anything out.
My OEM disc brakes were good and I recently put a Cordoba set up on it and they work even better.Check to see if you are having the front brakes hanging up after you release them. I had this problem on my Valiant and is was sluggish off the line. Fixed it and it’s great now.
Seems like this is my plan. Going Commando? Of course I’ll seek the wise council of the two major A833 suppliers/specialists.1 st ,2nd , 3rd gears, cluster, input shaft