Ok, Lets throw this out for comment! I am putting together a 31 S/W Chassis and I am wondering what would be the best choice a 3.78 or a 3.54 gear set. I have both. and lets add to the mix a gear splitter which I don't have. I am going to use this car for long range touring. The engine is a touring engine balanced and inserted, ect.
rear differential
- Thread starter woodlot1
- Start date
Patrick L.
Well-known member
Not that I can help much, but, I'm thinking the 3.78 with an overdrive and the 3.54 without.
Big hammer
Well-known member
You should use 3.78 with over drive, and sell me the 3.54 
TerryH
Well-known member
I have a Mitchell 26% OD, and a 5.5 HC engine, along with the 3.78 rear end. That setup works very well with many Model A's, and mine is a heavier Town Sedan. I can still pull modest hills in OD, and can cruise easily at 55-60 when needed. We do have some hilly areas in S. Calif., so I would not want the 3.54 unless your engine has substantially more power than the usual HC head provides.
midgetracer
Well-known member
I have very good luck with 3.54 rear ratio.
racingrufus
Senior Member
I have installed a 3.54 ratio ring and pinion gear set in my 1929 Special Coupe and I like it very much. I have a newly rebuilt engine with a 5.5 HC head, a Weber down draft carb, a header and a B model grind on the cam. I have no over drive and stock trans. I can cruise at 55 to 60 mph with no strain on engine. Dwayne
modelAtony
Senior Member
I have 3:54 in 29 roadster with pure stock everything else. It is ok but not a tour car. Have 31 Tudor with 3:27 and extra goodies this is a runner you would die for. This Tudor is another world away from a stock A. The experience you get is great , you have a car that you can go anywhere and really enjoy going any where you want. Have fun modelAtony tony white Lafayette, LA