[quote=2ndopp][quote=DaytonaTurbo] Some food for thought, a 408 or 440 has a very broad torque curve. A 2.45 first gear x .8 = 1.96. Second gear is 1.45, close enough that a good aftermarket torque converter should hide most of that difference. A 1.45 second gear x .8 = 1.16. Third is 1.00.
This is the point where we end the gear splitting discussion. It's not needed in a torquey engine with a broad rpm range.
The only thing I'd like to add to the 518 swap is there are many pros mentioned. I've done it and liked it, from a 904 to a 518 to a 5 speed manual.
The only cons against it is, it's not an efficient transmission. Without taking over the thread with my data I'll condense it. With my 904, excellent mileage but poor acceleration due to tall 1st and tall rear ratio. 518 was quicker due to steeper rear but the mileage was still poor, I blame the lack of efficiency, the only advantage was high cruising speed and low rpm due to tall overdrive. Finally the 5 spd gained me 3 mph in the 1/4 and 3 mpg while speeding.
Just want to add, if you go 518 you need a steep rear gear. The 1st gear is tall and so is the o.d.
