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.