3:45's vs 4:10's MPG

[Hammer]

For those out there that have made the switch from 3:45's to 4:10's, what kind of gas mileage change have you seen?

I'm driving to BG in May from Idaho and don't want to swap the gears right now if I will see a drastic drop in mileage. That could add substantially to the trip cost.

Thanks

[DaveK]

I have 4.10s and usually get around 25/26 on the highway. Depends on the weight of your foot though too

[Jagdpanzer]

Not seen much of a difference after installing 4.10s in my case.

Just do it.................. You'll enjoy your drive and get to use 6th gear.

[Hammer]

Mopar P5007043 viper gears, from where
http://www.trademotion.com/auction/index.cfm?siteid=214650&catalogid=0
Call Jeromy for prices, under $300 shipped.

[Hammer]

Why are the ARP studs being used?
have there been problems with the bolts? I know they are 20 years old but there are billions of cars with bolts running around.

Does the extra clamping force offered change the setup at all?

[Dynomite]

Originally Posted by Hammer

Why are the ARP studs being used?
have there been problems with the bolts? I know they are 20 years old but there are billions of cars with bolts running around.

Does the extra clamping force offered change the setup at all?

Jagdpanzer said do it and HAWAIIZR-1 did it

I am assuming you are assured full depth of the stud. Once stud is set you get full locking of the nut. One other advantage.....you are not turning the stud while applying the final torque on the nut.

These ARP studs would work great for Head Bolts to obtain more even torque. Does anyone use these ARP type studs for head bolts?

[flyin ryan]

Originally Posted by Hammer

Why are the ARP studs being used?
have there been problems with the bolts? I know they are 20 years old but there are billions of cars with bolts running around.

Does the extra clamping force offered change the setup at all?

Studs are obviously the preferred method, no disputing that, right? But I didn't bother with mine, ...unless a person is going to the ¼ mile often with good (sticky) tires, factory bolts are fine. If you want to do it, just because, only really need to the one side. The one cap takes all the load, other side is more or less along for the ride. Also if a person does convert over to ARP studs, better be absolutly sure to have the 'New' correct TQ. spec. & what lube to use. Another thing...Don't 'Double-Nut' the stud in tight to the case...Finger tight only into the case....VERY important!!

Originally Posted by Dynomite

OK already

I need Ratech 'Deluxe' Install kit-3012K from http://ratech.stores.yahoo.net/coax84d44.html

Mopar P5007043 viper gears, from http://www.trademotion.com/auction/i...50&catalogid=0 Call Jeromy for prices, under $300 shipped.

Marc Haibeck 13/43 speedometer gears from http://www.zr1specialist.com/HAT%20W...on%20Gears.htm

I convert the carrier caps from 1/2" bolts over to 1/2' ARP studs. ARP Part Numbers:
4 x Stud - AR4.060-LB
4 x Hex Nut - 200-8607
4 x Washer - 200-8514
To order I call ARP Order Desk & Technical Support: 800.826.3045
Use a 1/2"-13 bottoming tap to deepen the threads.

As long as I am there under the differential, I get a Denny's Driveshafts 1350 kit for C4 aluminum half shafts from http://www.dennysdriveshaft.com/p422...build_kit.html

Is that all correct
Is there anything else I will need
I already installed the differential drain plug from Corvette Central
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F

To permanently stop rust I use POR-15 Stirling Silver and Gloss Black paint
http://www.por15.com/POR-15-Rust-Pre...nt/products/1/

Are you going to consider rebuilding your posi unit? I only did it because I did not know the history and the mileage was only 53K but when I looked at the clutches once apart I am glad I did. If so, you will want Spicer # 707018X and here is a good source: http://www.drivetrainspecialists.com...oduct-446.html Many others sell it, but this was the best price that I could find.

As for the POR-15, no rust on the aluminum but I wanted to clean it up and it did not look very good after my other attempts. POR-15 is just an excellent product that I have been using for over 20 years and it is very durable as it will seal the aluminum from corrosion or discoloration. The yokes on mine were quite rusty and why I used it on that portion. If you are a purist/NCRS type then you will want to keep it all naturalllllll...........

[Dynomite]

Originally Posted by HAWAIIZR-1

Are you going to consider rebuilding your posi unit? If so, you will want Spicer # 707018X and here is a good source: http://www.drivetrainspecialists.com...oduct-446.html Many others sell it, but this was the best price that I could find.

As for the POR-15, no rust on the aluminum but I wanted to clean it up and it did not look very good after my other attempts. It will seal the aluminum from corrosion or discoloration. The yokes on mine were quite rusty and why I used it on that portion.

Thanks for suggestions on rebuilding the posi unit. I added Spicer # 707018X to my list in post #10 and I understand the use of POR-15 for rust. POR-15 on the aluminum housing of the differential does look great however

Originally Posted by flyin ryan

My point being don't set the stud in too tight! Double Nut/Broached top...tish-tosh . Finger tight is the way. If it doesn't go in cleanly with your fingers, run a tap or thread chaser through. Applies for all/everykind of studs.

I understand on cleaning the threads and not too tight on the studs after you mentioned it and I am thinking like Jagdpanzer suggests on rational for using ARP studs as well as using a 1/2-13 bottom tap

Originally Posted by Jagdpanzer

I converted to studs because stock bolt holes are threaded into the aluminum housing material without the benefit of inserts and I was worried the threads were not up to taking several disassembles and re-torques for adjusting the shims several times in order to find the optimum gear contact pattern and proper backlash. In my experience in addition to being more secure the studs makes the set up process go a lot smoother and quicker as compared to using the original grade 5 bolts. Your mileage may differ.

As always I stole information from other great theads so all the technical information is in one subscribed thread location

The sources provided by everyone (updated) for parts to install 410s are all in post #10 in this thread.

I put all the 410 information in Hammer's thread herein because gas mileage is always an issue with 410s. Not much is said for the best rational for switching to 410s (sixth gear becomes usefull at speeds under 75 mph)

Also, when Hammer installs his 410s I am hoping he will add pictures and suggestions here in this thread since he should now be convinced to install the 410s before BG. It will be interesting how Hammer shims and sets backlash to get that perfect contact pattern as HAWAIIZR-1 ended up with on his 410s (post #40). http://www.zr1.net/forum/showthread.php?t=7419&page=4

Rarely there are some issues related to over spinning the output shaft on the transmission with 410s which ZFdoc at billb@zfdoc.com has explained in detail on another forum. http://forums.*************.com/c4-z...at-find-2.html

The ************* do not mean X-rated which I just do not understand the use of ***********