F8L Z71

I did some math and this is what I came up with.

I run around on the street with 32-33" tall tires.

I race on 29" tall tires

If I do a 4.10 gear front and rear it is very similar to running 4.56s on a 29" tall tire. So for the best of both worlds I can do 4.10s and have a decent gearing but not take a huge hit in gas milage when using my street tires. When racing I can simply put my 29" tall tires on and have some fun with the equivalent of a 4.56 gear. Adding to that the 29" tall tires are simply the Centerlines off my RCSB and still look cool if I wanted to go "cruising" around town p[icking on Imports.

Now I need a little clarification on how to do the front. Can I simply pick up a front diff. from the junk yard out of an HD 4.10 equip truck and do the swap at Synergy? The rear should swap over readily also yes? They have a 14bolt vs my 10bolt though right? Any hastles with that swap?

00Silverado

I've only seen one person do the 3/4 ton IFS swap into a halfton. Obviously it would be nice to have a locking front differential for traction purposes, especially at the track, but I just don't think it would be an easy swap. The 9.25" front is a whole lot bigger and beefier than the 8.25. You might be able to get it to work, I haven't seen anybody do the swap in a NBS, so info is pretty much nonexistant.
For the rear you'll run into a problem again. If you want a 9.5" semifloat axle so you can keep your current wheels and 6 lug bolt pattern, you'll need to find one out of a OBS truck, and then convert that to disc brakes because the old trucks have drums. If you look at the rearends on the HD's they are all 8 lugs. I know a guy who makes a new hub that will allow you to run a 6 lug wheel on a 10.5" 14 bolt FF, but I don't know what he charges for the new hubs. If you're interested pm me and I can get you some contact info for him.
Hope that helped a little

Mr. Sandog

I thought Silverado VHO's had 9.5" rear gears with a 6-lug pattern?

00Silverado

Maybe they do, I'm not sure, if so, all you need to do is find a wrecked VHO f8l, but that might be a bit hard.

blownZ71

iTrader: (1)

I think Parish has some side by side pics of the 1500 and 2500 front diff's, and he said that they are quite a bit different. FYI

F8L Z71

Did Parish have front Diffs or the T-Case? I already have the HD T-Case

I'm starting to think it might just be best to do a regular gear swap. If I do that I might just go with 4.56s. Then I never have to run a smaller tire for racing but I'm scared of what it'll do to my freeway milage. It's about a 7mph difference at 2500rpm cruising speed between 4.56 and 4.10s. Well according to an online calulator.

4.56s would feel badass for around town driving though!

F8L Z71

Ok, so I mounted the 20's on the Z71 today and drove to work. My verdict? I need gears BAD! The 29" tall 20's effectively gave me a 4.10 gear ratio and it feels much better. It's still a bit soft on the bottom end but it's a huge difference over the 32" tall tires.

I called around and got prices all over the map. Prices ranged from $3000 to $1200. I had called a place before and it was $1500 so I'm gonna bite the bullet and do 4.56s

mzoomora

iTrader: (31)

If you are going to do gears only rather than change housings let me know.