rear gears 3.25 and 3.27

J

johnneilson

Well-known member
I have been looking for information on when the 3.25 and 3.27 gears were available. These would be for V8 "straddle mount" rearends.

And what cars they were offered in.

Thanks, John
 
I have seen 3.25 offered aftermarket for 35-48 with six spline pinions. I had a friend with this ratio in a stock 47 sedan and it wasn't optimal, not terrible but not optimal.
 
I got 3.25 gears from Van Pelt for my '41, as a cheaper and more reliable alternative to a two speed rear end. They got me the highway cruise RPM I wanted and are fine in traffic and on hills, - BUT, I have a 284 inch engine with a ton of torque. The 3.25 will probably be too tall for a stock engine.
 
3:25 is just about too tall for my 51 Merc engine in my truck. I ran a 3:50 that I liked better but changed to the 3:25 for speed or so I thought. for hill starts it is tough on the clutch and the torgue curve is off, but boy will it rum down the highway-run away and left my buddy in his new chev pick up. he said 80 mph was too fast for the highway
 
I am very happy w/the 3:54's that I put in my '37 w/a stock 221 cu. in. engine. I got the gears, install/rebuild rear end kit,& spline adaptor from Mac VanPelt. I recommend them as they sell good quality parts at a good price along w/good customer service! - F F
 
A friend in WV. had 3:25 in a 39 coupe and on the interstate he run 70 and no problem in the mountains. Another friend put 3:25 in a 40, 2 door sdn. stock engine and he loves them. Lots of hills around here. I see no problem using 3:25 in a flathead.
 
Well, the question was not answered, thanks.
FWIW, I use 3.25 in the race car QC Halibrand rear end.
At Bonneville, ran 174 mph with a slightly modified Model "B" motor and 2 speed trans.

J
 
Not apples to apples, but I owned a 50 Plymouth for 36 years. 90 hp which is comparable to the stock 40 v8 but with more torque. I swapped from 3:90 gears to 3:70 gears, then 3:70 to 3:54. That worked out very well with out having to slip the clutch a lot. I know I would not have been happy with 3:25 gears where I live. The 15" tires I had on it was comparable to 6:00x16s. Just my experience on a similar swap. I then added overdrive and it would cruise at 70 nice.
Stay safe
Steve
 
what we seem to be missing here is tyre size or dia as this often has a greater effect on how the vehicle drives as there is a large difference between a 700/16 and a 550/15 To find the optimum for you start with tire rpm x at what ever you want to cruise at then calculate backwards to eng sweet range generally the taller the tire the deeper the ratio required
 
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