I have been looking for a set of rear ends gears fror my 68 firebird. The car came with 3:36. I would like 3:08 or 3:23 or something like that. The closest I could find is 3:55. Anyone else find some better highway gears out there?
I hate to be a kill-joy, but most aftermarket 10-bolt 3.08 & 3.23 gear sets are only for the Chevy-style differential and tend to take a little bit of work to adapt to the BOP. (But it can be done.)
You probably will have to look for NOS or good condition used gears.
No doubt there. The easiest way to tell the difference is the pinion spline. The Chevies have 25 and the BOP have 27. You may get lucky on eBay because people are getting rid of the higher gears. Jim
The difference between the 3.36 and the 3.23 would be so slight, you may not notice an improvement in fuel economy, if that is your goal. It's only a 4% change in ratio, which would mean that your engine speed, currently 2000 rpm, would drop to 1920 rpm. The payback on a new set of gears would be quite a long time.
What does the car have in it now?
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
If you're going for mileage and you have a 1:1 top gear (like 3rd in a TH350/TH400) then I can't stress highly enough that you get 2:56 or 2.78 gears. The 2.78 gears are still high-revving for extended highway driving at 70+ MPH. I can just imagine what 3.2x and higher gears are like. Yikes!
I had 3.23's in a 4 spd car and got just over 15 US mpg at 85-90 mph with an 041 cam and ported #48 heads. It was fun watching the speedo needle sweep past 100 mph in third!
I have a 2.56 gear set that is coming out for a set of 4.10's. I don't know the present condition but if you're interested I can have a look.
Nothing wrong with high speed in a good car with a capable driver.
I did one high speed run at 150+ down I-75 many, many years ago, and plenty of 120 mph up M-53 and I-696. The roads were bad then, but are worse now. One of our famous potholes at 150 would not be a good thing, nor would an encounter with the all too common oblivious driver.
I need a stretch of open road, and a nice dry day. I wonder what speed convertible tops are rated for?
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
We can give the thread back. I'll have the bushings done by Friday. Now where did I hide that credit card?
LOL, I wanted the Global West but just couldn't do it. So many things to buy, so little cash to spread around. I had to settle for Energy Suspension. Even they will be far superior to deteriorated 37 year old rubber.
And with a 2.78 rear, the top end is pretty high on this car.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
I pulled the original 2.56 & worn out cone posi to 3.55 earlier this year. Purchased new eaton posi and Richmong gears from these guys on their e-bay store: http://www.rearendparts.com/
If you have 3.36 gears you are dealing with the 8.2 BOP. You need to change the carrier if you go numerically lower (although I've heard you can get adaptors). I do not think anyone makes new 3.36 gears. Only new BOP gears are 3.55, 3.90 and up.
3.55's with TH400 is a blast of the line, but not much of a highway cruiser. Mine revs about 3200 @ 70 mph. Overdrive would sure be nice.
Vikki, mine handled numerous 140+ runs. Gets very noisy, can't hear the engine!
I had a cone posi and four pinion carrier with 3.55 gears. I'm not sure I want to know what they would be worth now, I sold them cheap about twenty years ago.
Here's a deal on some highway gears! $100 for the whole rear end. Classical Pontiac today.
This is the original Non Posi rearend 10 Bolt 8.2 with 2.78 gear. Used condition and functional when removed from vehicle. $100 or best offer. Need the garage space. Rearend is located in the Chicago vicinity, pick up is preferred, but I can deliver local only if necessary. Revised - Many an offer, it must go!
Name: Mark State: IL Country: USA Phone: 2627451142 Email: boratto@trostel.com Posted: 11/10/05 Number: 110348
