Joined: Thu Feb 24 2011, 12:55PM
Location: London, UK
Posts: 152
A friend of mine will shortly be swapping another 440 into my 66 Polara that has just been rebuilt at + .040 with Edelbrock Performer RPM aluminum heads and a Lunati Voodoo 10230703 cam, plus there is a 2400 stall to go with it. At present I have the slightly milder 10230702 cam and a 1800 (possibly 2000) converter. I'm running with 275/60/15's on the rears.
This is a street car and currently has 3.23 gears and with these it is quite nicely balanced. But, I also have the opportunity to swap these out for a set of 3.55's. What do you think...3.23 or 3.55's with this new setup? I've heard some people say that they have felt little difference moving from 3.23's to 3.55's, but others have said it has made cruising at 65-70 tiresome. I was thinking 3.55's are not too steep and still pretty sensible for a street car.
Joined: Thu Oct 07 2010, 12:01PM
Location: vermont
Posts: 180
For bopping around locally 3.55s are more fun, but if you're going to be doing a lot of highway driving then 3.23s make more sense. From a performance stand point with your particular set up 3.55s probably get you into that cam more quickly, I'd go with the 3.55s, and if you really dislike it you can always switch back, my 2 cents.
Joined: Wed Nov 17 2010, 03:28PM
Location: florida
Posts: 1311
tire size plays a roll in gearing so what size tire are you thinking? i personally like 3.91 gears but thats me.i think you will like 3.55 with a 28 " tire.
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
yabadaba wrote ...
Yes indeed. That's a must for me....they transform the driveability hugely imho.
OK, I figured if you had the 3.23s but no PTK, you might be happy adding that. I went from a 2.76 open to 3.23SG and installed a shift kit and PTK module at about the same time. Between those changes, my car was a lot more fun to drive around town. The engine spends a lot more time in its power band.
3.55 would be the way for me.That being said if you do a fair amount of highway driving you can always run a 255/70R15 on the rear.1 inch taller and that would drop you rpm back to where it is currently at cruise.
I may be a little late to the party; but I recently made the switch from 3.23's to 3.55 in my 67 300. I'd recommend it! At first, I could really tell the engine was reving higher in all my driving but I've gotten used to it. Nice thing about it is that I can hear the exhaust more now, especially at mild cruising speeds of 55 to 60 or so. I was skeptical about it at first because I thought my fuel mileage might suffer. With the 3.23's it was about 10 to 11 mpg and since I've changed, the fuel mileage is pretty much the same.
The car is definitely more lively in acceleration at all speeds AND, something I didn't think about, there is also more engine braking when I take my foot off the gas. Don't have to use the brakes so much to slow down!
The steeper gears aren't tiresome on the highway because my car's ambient noise level at cruise is pretty high anyway. All I hear is a more pleasant sound form my exhaust.
In summary:
Better acceleration at all speeds Sounds better Better deceleration when you want to slow down Seems be no penalty in fuel mileage