My 29 rpu is to slow and i want to change the ratio, i Think the pickups got 4:11 original. I have a 59AB with dual carbs and Evans heads. What do you Think aboute the 3:27 ratio, to much or just right?
My only experience with the two gear ratios you are working with was when I was young. I had Two 1965 gto's at the same time ,the tripower car had 4.11 and the 4bbl had 3.23 The 4.11 car was fun to drag race but the 3.23 car was a much better geared for the highway
I'm planning on running those same gears in my A rear end. I'm running a '51 Dodge 230 with dual carbs and stock trans. Should scoot along nicely. Only thing is that $640 price! Ouch! Posted using the Full Custom H.A.M.B. App!
What tires? Trans? Those gears will be much nicer than 4.11s, but if your tires are too tall it'll kill any power you've got. Figure out where your torque peak is and gear it to run in that range.
I have not tried 3.27's, but bought new 3.54's for the delivery. Hoping to find a good used set of 3.54's for the business coupe also. I think a lot depends on the terrain you travel most and the HP of the engine. Although I live on the flatlands I do intend some trips to the mountains in both and 3.54's are a good compromise in my opinion. The 4 banger should be near 90 HP when done and likely the flathead will be a little over 125 HP. Rod
Another vote for checking rpm. I have 3.25 Ford banjo with 7.00 X 16 tires and it is too tall of a gear. 1932 roadster with 265 V8 and 1939 Ford tranny. Have to be going about 45 mph before it will pull high gear. That means running around in 2nd a lot when speedo is 35 or 40 mph. When you make a slow turn in 2nd it will bog. Works great on the highway though!
the 3:23's are going to improve your highway driving a lot. Will be a lot quieter and just more pleasurable to cruise. Coming off the line in a drag race is going to be a handicap if your racing someone with a 4:11 gear. If I remember you have 16" tires which will be fine with the 3:23's. What trans is in your pick up. I don't remember if it was updated or not.
I always use 3.25 or 3.27 .... A flathead has a lot of torque (more than a 265 sbc) And will pull the car easy.... 32 roadster with 32 box , 59ab and 7.5 x 16 For example
The important part is your first gear ratio in your Trans , unless it is a overdrive your final drive will be 1:1 so if you do some home work you can tailor your 1st gear ratio . I have a later GM 4 speed Trans with a 3.11 first gear and 3.00 rear gear in my model A .pulls real hard off the line but still cruises at 2200 rpm at 70 mph
My Zipper has a strong banger with a '39 transmission and Zephyr gears. Tried the 3:27 gears and was very unhappy. Traded for some 3:54 gears and got the right combo for street/highway driving. As others have posted, consider your RPM's and tire diameter. If you do swap gears, the 4:11 set definitely has value to the Model A hill climb guys.
My A Has a stock 51-52 Merc about 110 HP, 46 car gears in the 38 top loader, and 4:11 rear. My rear tire is about 31 inches, (thats tall). The car is very quick in first but spools up so fast you run out or rpm very quick in first, second is only good for about 35, and the rest is third. I can't tell you actual cause I don't have a speedo, but I don't think I've seen 80 in 10 years trying not to shake the flatty apart. What you can do is drive the back roads where I live, and run up and down good size hils all day at 20-60 without ever shifting into second. It's really about how you want your car to drive, where you want to drive. If I was to change the ratio it would be to 3:54, which would give a little more time in first and second, and a little higher speed top end for the same rpm. Just my $.02
Bought a stripped down '31 roadster decades ago with a hot banger and a 15/29 gearset with 32 wheels. The car was light and had no expectation that there was a 3.27 rear gear as it seemed normal. Had other As at the time and they all had 3.78s with other A gears. Because the roadster was light, the gears were great, but would have been too much for a heavier car. The V8 would have higher revs, allowing higher road speeds than my banger which would cruise at the 60MPH sweet spot. These days I step up to the overdrives with 4.11s to get better performance at all speeds. Remember that 3.27 is just a number, and that the other issues like tire size and car weight, among many other things make up the total performance. Serious torque helps cover for bad gear choices by brute force. Use it if you got it! Good Luck: Fred A
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