----- Original Message -----
Sent: Monday, December 29, 2003 3:53
PM
Subject: RE: [Chevelle-list] rear
gears
Bill,
The "CR" code is for a 3.70 posi, 1109 is Nov 9, and B is Buffalo
assembly. I'd suggest you look at http://www.chevellestuff.com/generic/rpm_calculator.htm and
play with gear ratios to find what'll work in your highway speed ranges.
If you know your tire size, you can play with ratios available and see what
RPM's you'd be running at a given speed. Transmission type selection is
moot since you're looking at a 1-to-1 ratio in high gear unless you want to
toss in the variable of an O/D transmission. Being an automatic, you
might want to allow 200-300 RPM for converter slippage as
well.
For example with all things being equal (assuming a regular
205x70x14 tire), 3.70's at 75 give you about 3700 RPMs while a 3.31 drops that
to 3300. Swapping to an O/D (such as a 700-R4) and keeping your 3.70s
drops your RPMs to 2600 in O/D at 75. I used this page quite a bit when
I was deciding what rear tire sizes would work for me.
Dale McIntosh
TC Gold #92/ACES #1709/NECOA #41
67SS/67 Elky
Dale�s Place � My 67
SS and 67 El Camino
ChevelleStuff � Decoding info on 64-72 Chevelles
Team 67 � 1967
Chevelle/El Camino Specific
Midwest Chevelles � Midwest Chevelle Show Information
hi gang
I've got a question or two regarding the
gearing of my differential.I've got a 67 Malibu that had a 283 and a
powerglide, I've pulled them and installed a 305 and a TH350. My question is
this "what would you recommend for the gears in my rear end"? I'm looking to
decrease my rpms on the long haul and increase my mileage.to the best of my
knowledge my gears are stock.
any help would be greatly
appreciated
it looks like the casting on the rear end is
"3894938N" ? its a non posi 10 bolt
stamped on the tube it looks like "CR1109B" or
could be "cr11098" ?
hope this helps
