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I always get a kick out of the 3.73 vs 3.54 debate. I have a 96 Impala SS, it has an iron headed LT1 and the same trans as a Vette. It's my family/work ride. I installed 3.73s in it along with a 2500 RPM converter and a Trans-Go shift kit. How anyone would want 3.54s in an LT1 Vette is beyond me :cheers:
Eric
I went 3.54 for 2 reasons. 1. I got the rebuilt diff. from zip for $759.00 and everywhere else I was looking that sold the 3.73 diff., IE: MAD, Ikerds, etc. was $1295.00 2. After talking to Justin, at Zip, he said the 3.54 holds up a little better then the 3.73. It has to do with the larger pinion gear. Call him and he will be glad to explain it to you.
I dont understand why there is such a debate between the 3.54 and 3.73. There is less then 5% difference in the two. Yes, I would have perfered to have had the 3.73 but not for the price difference and then, what Justin explained to me was icing on the cake. By the way, the 92 LT1 auto Vette that TPIS uses to test with has the 3.54 gear in it.
...what Justin explained to me was icing on the cake....
Justin also claims you shouldn't have a drain plug in your Dana case because it will weaken it to the point where it will not be strong enough to hold up under load. But if you look at 600HP road race Vettes, they have at least 2 holes for the diff oil cooler. He seems like a nice guy, but when he makes claims like this it makes me wonder. He should speak with the E-town boys who ran over 200 sub 13 second runs on their Dana 36s with 3.73.
OK Fella's The deed is done. I went with the 3.73's and I have an appointment for installation next Thursday. I will keep you posted on the results. One year unlimited mile warranty is not too shabby I guess!
Hey by the way, What about the RPM's at around 65 or so. Anyone have any info for me? :yesnod:
...What about the RPM's at around 65 or so. Anyone have any info for me?
It's a linear relationship. If you had 2.59, then to calculate the new RPM with 3.73 just multiply the old RPM at 60MPH by 3.73/2.59 or 1.44 to get the new RPM with 3.73. If your old gear is 3.07, multiply the old RPM with 3.07 by 3.73/3.07 or 1.21 to get the new RPM with 3.73.
IMHO, you are adding one of the two most important mods, the other being a looser torque converter. I have a 2,500 stall speed converter in my Impala SS (with the iron headed LT1) and that combined with the 3.73 gear have made more difference than all of my other mods out together. A shift kit is another get mod, esp after adding the looser TC and the lower gears.
I appreciate your help! I will also consider these other mods. For now I'm looking forward to the new gears and will be back to post the turnout!!!
Thanx fellas! :D
Yes, let us know! I also have the 2.59's in my '96. Although it has great off the line acceleration, I'm sure there is room for much improvement. :yesnod:
I was leaning towards the 3.07's but who knows...
..I have 3:73's/shiftkit and it's my daily driver...plus I take road trips (last one was 1800 miles)..averaged 24-25 mpg...as for the difference you'll feel, I'm just waitin' for your "Holy Moly !!!" post the day you pick the car up... :D ...good luck