You're right, that's a pretty nice gain for being able to keep the 486s. Who knows, by the time I make up my mind I might redo the whole rearend anyway. It's spooled with the 486 gearing and spends almost all the time on the street anyway.
So what would be the hot ticket for that ride if I don't want to kick down the bones for the GV.
So considering that I'm clueless with the math, what do you guys think is a good all around street gear.
So. Cal. freeways AVERAGE at least 75 mph. I feel I wouldn't get plowed if I were cruisin at 65 minimum.
IMO with your set up 4:30's may be the way to go. Still a fantastic ratio, you drop a bit of aggression from the line. I have no idea how you hook up now, with those huge fats at the back I would imagine you have no problems with your hook up so maybe 4:56 gears too. Below are what you would gain by going to 4:30's and 4:56's.
4:56 gears would give you an OD gear of 3.55
4.30 gears would give you an OD gear of 3.35
With 4:56 gears @ 75mph in OD = 2710rpm (just a tick over 2700rpm).
With 4.30 gears @ 75mph in OD = 2560rpm
Without the Gear Vendors unit and a gear change to either 4:30's or 4:56's:
4:56 gears @ 75mph = 3480rpm (Over your 4:86 gears is a 200rpm decrease)
4:30 gears @ 75mph = 3280rpm (Over your 4:86 gears is a 430rpm decrease)
IMO 4:30 would be the way to go to see a major difference, 430rpm drop is very good.
3.55 with your set up and or 3.35 are very good for the car you are driving.
Even in stock form (440-4bbl) making stock hp/Trq 3.35 gears offer good mph and mpg on the highway.
The Gear Vendors unit is $2,395 give or take $50 on where you buy it from.
Considering the price of the Keisler products this is one hell of a price, you do it once and that's it.
I have heard they are bullet proof while doing my own searches (from well known car guys on other forums).
Hope that helps.