4.3L, nv3500 with 4.56
10-05-2017, 01:53 PM
#11
not for a truck, and besides, t56s have way higher gearing than the nv3500s
this would apply more for the GTO T56, since the Z06 version was designed to bolt to the diff instead of using a drive shaft, but you're on the right page. the M12 also had a .57 6th.
another huge thing to consider is that the cars use 25-26" tires where he's running a 32. and don't forget the extra 1000lb the truck weighs.
most guys swapping to T56 run 4.88s or 5.13s, so 4.56 is on the higher limit & seen more with M12 gearing, however, most recommend going to the 14bolt for lower than 4.56 just for ring/pinion strength.
i'm using 4.30s with my nv3500 and 33s - drives about like the stock 245s with 3.73 rear. highway cruising likes to sit more around 60-65mph (~2000rpm) for lowest noise & better gas mileage, but it'll get out of its own way in 5th & shoot right up to 90-100 easy... even with just a tuned 5.3.
you should be fine for now with 4.56 if it's mostly in-town driving.
The T-56 in the F-bodies were mostly 2.66:1 with the 3.90s the final 1st gear ratio would be 10.37:1.
4.10s with 2.66 1st gear 10.9:1
I run the 4.1 rear and 3.06:1 1st gear for a 12.55:1.
The T-56 in a ZO6 is RPO M12 and has the shorter 1st gear than the other transmissions. It has the 2.97:1 1st gear ratio. With a 3.90 rear gear and 2.97:1 1st gear of the M12, it gives a 11.58:1.
You 2 are comparing 2 different ratioed transmissions.
You also have to gear for the T-56 fir its super high 0.50:1 6th gear. This is where the lower 4.1s work great for cruising. Shifting from 4th to 6th cuts engine rpm in half.
peace
Hog
4.10s with 2.66 1st gear 10.9:1
I run the 4.1 rear and 3.06:1 1st gear for a 12.55:1.
The T-56 in a ZO6 is RPO M12 and has the shorter 1st gear than the other transmissions. It has the 2.97:1 1st gear ratio. With a 3.90 rear gear and 2.97:1 1st gear of the M12, it gives a 11.58:1.
You 2 are comparing 2 different ratioed transmissions.
You also have to gear for the T-56 fir its super high 0.50:1 6th gear. This is where the lower 4.1s work great for cruising. Shifting from 4th to 6th cuts engine rpm in half.
peace
Hog
most guys swapping to T56 run 4.88s or 5.13s, so 4.56 is on the higher limit & seen more with M12 gearing, however, most recommend going to the 14bolt for lower than 4.56 just for ring/pinion strength.
i'm using 4.30s with my nv3500 and 33s - drives about like the stock 245s with 3.73 rear. highway cruising likes to sit more around 60-65mph (~2000rpm) for lowest noise & better gas mileage, but it'll get out of its own way in 5th & shoot right up to 90-100 easy... even with just a tuned 5.3.
you should be fine for now with 4.56 if it's mostly in-town driving.
10-05-2017, 02:46 PM
#12
I've got 4.56 with my f-body t56, 1st is pretty fun and its useful too. I run a 31.22 inch tire so it gets going pretty easy in first, very easy on the clutch. Check out the attachment, it an excel doc i found on here and modified it to show what i wanted to see.
10-09-2017, 09:03 AM
#13
I have a LQ4 with a NVG4500 in my truck right now with the 3.73.
First is a steep 5.61:1 so its only good for hills and trailers. Still sometimes use it.
The OD is .75:1 and thus the truck is a bit sportier on the highway.
The T56 has a much nicer shift and would love to have that in the truck but the tranny isn't durable and if you want to keep 4WD only one guy makes a kit and its more than 5 grand.
First is a steep 5.61:1 so its only good for hills and trailers. Still sometimes use it.
The OD is .75:1 and thus the truck is a bit sportier on the highway.
The T56 has a much nicer shift and would love to have that in the truck but the tranny isn't durable and if you want to keep 4WD only one guy makes a kit and its more than 5 grand.