these are marking on the dif of a ford 9” I’m planing to use and I need help identifying them, these pictures were sent to me so this all I have at the moment. Trying to figure out the gear ratio if that’s possible All help appreciated. I see, dif 17, 4210, 4025,
Not much to go on....they often had the gear tooth counts stamped on the ring gear, but not in that picture (although it looks like we can see the beginning of it, "4", at the bottom of the picture). The ring gear is really thin, so it's probably a 2.75 ratio or close to it. The housing casting engineering number of C1... indicates it's probably a 1961-66 center housing, since C7.. was pretty common, and it came out it 1967. Yet the gears are D2... which is 1972 or later. The loose pinion nut means it needs some work...I'd put a new crush sleeve and some seals in it at the least, and inspect the bearings to see what else it needs.
It’s a shop being rebuilt I purchased the case and third member for 150 and a shop is doing the rebuild but I haven’t had time to ask the gear ratio. 2.75 might be too high for application as I’m running a C-6 and 427 stroker in front of it.
You might want to ask them, before they get too far along with it I just made a wild guess on the gear ratio. But a 4.11 ring gear is much thicker...here's a 4.11 on the left, 2.75 on the right. The ring gear thickness is related to the gear ratio, because of the number of teeth on the pinion gear. Fewer pinion teeth (and smaller diameter pinion gear) on the steep ratio gears, more (and larger diameter pinion gear) on the highway gears. But yeah, call them up and talk about ratios.
My fuzzy memory says 3.25:1. Just count the ring gear and pinion teeth. Divide one by the other, and Bob's your uncle.
If its an earlier case as Squirrel has alluded, then it may have a 28-spline carrier vs. the stronger 31-spline unit. If you already have axles and a rear end axle housing, I would confirm the spline count on this unit is going to be compatible before investing more $$ on rebuilding it.
Okay 3.50 would be an ideal ratio and would work perfect for me. I was initially told by the person I purchased it from they believed it to be 3.30 - 3.50.
If you have it at a shop being rebuilt why don't you contact them and ask what ratio it is and if it's not what you want them have them set it up with your choice?
It was just dropped off and I they haven’t had a chance to go through completely yet so I was just hoping for some answers before hand. Sorry
What would be a recommended gear ratio I was planning on 3.30-3.50 for primarily street use and freeway. I’m running a C-6 with a TCI Super street fighter torque converter.
You don't believe on ring an pinion gear ratios when you have them in front of you. you count the teeth or read the stamped numbers and know exactly what you have. I have my wonderments about the outfit you are dealing with.
It’s a 53 Ford customline with a 427 stroker, c6, TCI super street fighter torque converter, and this 9”. That’s about as far as I’ve gotten I don’t tire size at the moment.
With a 427 Stroker what more would you need if just cruising around..But I don't know how the torque converter you have is supposed to behave..
I am not real familiar with Ford stroker motors. What you need to know to decide on gear ratio s the operating range of the motor plus tire diameter. For a trade off on most moderately built streeters a 3.26 to a 3.55:1 gear works real well in my experience. But that is just my experience and not a pure science. Just noticed that your gear is a 3.0? I ran a 3.08 ( about the same gear) behind a motor that has its sweet spot in the 3,000 to 3,200 range. With a 28" tire that put me about 80 or so cruising on the highway. If that is any help at all.
The motor was built with primarily street in mind for this car specifically so it’s a mid range setup and so forth, the stall is suppose to be around 3k depending on setup and I’m planning on 27”-28” tires.
Cam #s J. DIAM: STD INT EXH VALVE ADJUSTMENT HYD HYD GROSS VALVE LIFT .620 .604 DURATION @ .006 TAPPET LIFT 283 293 VALVE TIMING OPEN CLOSE @ .050 INT 9 41 EXH 53 5 SPECS FOR CAM INST. @ 106.0 CENTERLINE INT EXH DURATION @ .050 230.00 238.00 LOBE LIFT .388 .378 LOBE SEPARATION 110.0 FIRING ORDER STD ROCKER ARM RATIO 1.60 1.60
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