Now have 3.50 and 4200 converter, 3300 lbs. 6400 thru traps at 137 What would be a good 1/8 mile gear? Motor has lots of passes (600+) so want to keep rpms 6400 or bit less. 4.30?
I have 4.30s in my 8.5.....3650 lbs in the 1/4 mile I went through 6500-6600 at 126 in the only full pass i made. 3500ish launch 5000 stall............I shift about 6700 and go into high gear about 500 ft out. Standard gears in th400
I have 4.56 gears in my 12bolt, does 6.9 in the 1/8mile and 10.8 - 10.9 in the 1/4 mile. Have a 9"4000 TSP stall convertor. car weighs 3800lbs
This may or may not help because at the time I only had a 350 in my car so it's no real life comparison to your power. I had 3.73 gears in it and was going through the traps at around 6,200 or so in 2nd gear, above my peak hp and I could feel it dropping off. If I went into 3rd I always ran slower so I switched to 4.10s so I could get into 3rd gear but my times never got better because now, although I was getting into 3rd gear, I was going through the traps and a much lower rpm, below my peak hp. Go to www.wallaceracing.com and run some numbers where you'd like your rpm before you make a change.
4.30 gear in mine, goes 10.60’s at 124mph in the 1/4 and 6.60’s at 100mph in the 1/8. Traps 6200 in 1/4 and 5700 in the 1/8. Tire is 31” with an 8” converter