3.23 Open 8.75 diff needs to go
3.91s are perfect for around town, especially with a higher than stock stall, because the engine is always ready to rock, right off idle.
But I'm no fan of 70=~3510@3% slip for more than a few minutes. That is of course an opinion. Many here on FABO are willing to make that choice.
I like 3.23s with a 2800stall: in First gear, getting off the line, it will do almost whatever 3.91s will with a stock~2200 stall;
Have a look below; this is a 5.2Magnum, but you'll get the idea;
at 2200, the torque is ~280ftlbs/117hp
at 2800, the torque is ~292ftlbs/156hp
That's quite the increase in power; plus 33%.
At zero mph, and in 2.45First gear, that 292@2800 becomes 2311ftlbs into the rear axles with 3.23s. and
at zero mph, and in 2.45First gear, that 280@2200 becomes 2680 into the rear axles with 3.91s..
Now 2680 over 2311 is plus 16% to the 3.91s; good deal.
However, at 2800 the engine is making plus 33% power.... so the TC is gonna increase it's Torque Multiplication business slightly.
Will it be 16%?
IDK
But I'd be willing to try it, just to keep the cruising rpm down to 70=~2900 versus 3510, that's about 610 rpm right there.
The other thing is this; 3.23s will get you 65mph at about 4400@15% slip in second gear.
but with 3.91s it will be closer to 5300, which is a win-win situation, namely; plenty of tirespin in first gear, and about the right rpm to ET well in the zero to 60 speed-contest.
So IDK
You'll have to make the call.
Happy HotRodding..........
I tried to get rid of this lil pic but couldn't figure it out, sorry
I'm baaaak, lol.
3.91s are perfect for around town, especially with a higher than stock stall, because the engine is always ready to rock, right off idle.
But I'm no fan of 70=~3510@3% slip for more than a few minutes. That is of course an opinion. Many here on FABO are willing to make that choice.
I like 3.23s with a 2800stall: in First gear, getting off the line, it will do almost whatever 3.91s will with a stock~2200 stall;
Have a look below; this is a 5.2Magnum, but you'll get the idea;
at 2200, the torque is ~280ftlbs/117hp
at 2800, the torque is ~292ftlbs/156hp
That's quite the increase in power; plus 33%.
At zero mph, and in 2.45First gear, that 292@2800 becomes 2311ftlbs into the rear axles with 3.23s. and
at zero mph, and in 2.45First gear, that 280@2200 becomes 2680 into the rear axles with 3.91s..
Now 2680 over 2311 is plus 16% to the 3.91s; good deal.
However, at 2800 the engine is making plus 33% power.... so the TC is gonna increase it's Torque Multiplication business slightly.
Will it be 16%?
IDK
But I'd be willing to try it, just to keep the cruising rpm down to 70=~2900 versus 3510, that's about 610 rpm right there.
The other thing is this; 3.23s will get you 65mph at about 4400@15% slip in second gear.
but with 3.91s it will be closer to 5300, which is a win-win situation, namely; plenty of tirespin in first gear, and about the right rpm to ET well in the zero to 60 speed-contest.
So IDK
You'll have to make the call.
Happy HotRodding..........