Rear end decision help
Thread Starter
Racer
Joined: Nov 2013
Posts: 338
Likes: 8
From: South NewJersey
Rear end decision help
My engine is fresh built 355, makes power from 2300-6500 rpm with a 3000rpm T/C to a heavy duty built 700r4. Now I need the right gears to get me off the line the way I want. My engine builder suggests 3.73-4.10. I was hoping while gears were being installed I could have my early model dana 36 strengthened. If some of you can let me know what you have been though it would be great. I guess I will need to go to a local shop so I hope to have all the info I can get so I am not totally at there mercy. thanks
I rarely drag race but always drive enthusiastically and never driven as a daily driver.
I rarely drag race but always drive enthusiastically and never driven as a daily driver.
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
My engine is fresh built 355, makes power from 2300-6500 rpm with a 3000rpm T/C to a heavy duty built 700r4. Now I need the right gears to get me off the line the way I want. My engine builder suggests 3.73-4.10. I was hoping while gears were being installed I could have my early model dana 36 strengthened. If some of you can let me know what you have been though it would be great. I guess I will need to go to a local shop so I hope to have all the info I can get so I am not totally at there mercy. thanks
I rarely drag race but always drive enthusiastically and never driven as a daily driver.
I rarely drag race but always drive enthusiastically and never driven as a daily driver.
You don't mention what's in it for gear now so ..........
If it's a 3.07 what doesn't it do now to suit you?
If it's less than a 3.07 it's pretty self explanatory. If I had a driver I might be looking to do maybe a 3.45 or 3.54 D44 change. I believe that if a person shops hard it can be done reasonably.
Any D36 build is going to require likely a thick-gear kit, install kit and a clutch-pack plus labor. A 3.45 or 3.54 build you could drive and experience the ratio change first and then make choices. If you stumbled upon a 3.33 ratio from an '89 or '90 that might be a good choice.
If you have a 3.07 presently it should sell well.
Thread Starter
Racer
Joined: Nov 2013
Posts: 338
Likes: 8
From: South NewJersey
Sorry it is a 3.07. from what it feels like now I really think at least 3.73 or higher(numerically)will give me whaty I am looking for off the line. Once I get the engine high enough in the rpm range its great but now its like I'm waiting for it to "get there". I pretty sure I know where I want to go as far as what gear I just don't want to just put them in my stock rear from what Ive read there are mods you can do to strengthen it and I want to find out as much as I can before getting someone to install them . thanks
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
Sorry it is a 3.07. from what it feels like now I really think at least 3.73 or higher(numerically)will give me whaty I am looking for off the line. Once I get the engine high enough in the rpm range its great but now its like I'm waiting for it to "get there". I pretty sure I know where I want to go as far as what gear I just don't want to just put them in my stock rear from what Ive read there are mods you can do to strengthen it and I want to find out as much as I can before getting someone to install them . thanks
If you wanted to or needed to do a 3.73, 3.90 or a 4.10 in the D44 later the parts are more readily available and less expensive. The 3.73 is I believe the final/highest numerically available for the D36.
It's money much better spent particularly if you feel you actually "need" the gear.
Thread Starter
Racer
Joined: Nov 2013
Posts: 338
Likes: 8
From: South NewJersey
I knew someone was going to bring up the idea of a Dana44. I just thought the whole process of converting an entire rear end batwing and all wasn't worth the effort or cost for what I was trying to get. I rarely go to the track so most of my "heavy" launches are from traffic lights and I don't ever plan on putting sticky tires on it. From what Ive read on hear over the last decade I know there are things to be done to a Dana 36 to make it more durable I just don't know exactly what they are.
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
I suggested the change because a substantial amount of the initial cost can be offset with the sale of the 3.07 D36. Take it apart to build and you've got a $15 gear set. Maybe!!
If you want to do a D36 then I'd buy a housing, a carrier, clutch pack, new pinions and build the ratio of your choice to a point. You'll find 3.73 more frequently available than 3.54 and nothing steeper.
I don't believe there's actually anything that's undesirable with a D36 except that "no one" maintains them. I didn't suggest that you do the D44 because it was needed but rather that it's certainly got more options to alter the build if you wanted.
If you decide to build a D36 I have a housing, a rear cover but no carrier presently. I might have one set of pinions and washers. Pay the shipping & $50 for the housing and rear cover if you want to start collecting.
The rear doesn't care if the launch is from a traffic light or a race track, when it decides to retire it will quit.
If you want to do a D36 then I'd buy a housing, a carrier, clutch pack, new pinions and build the ratio of your choice to a point. You'll find 3.73 more frequently available than 3.54 and nothing steeper.
I don't believe there's actually anything that's undesirable with a D36 except that "no one" maintains them. I didn't suggest that you do the D44 because it was needed but rather that it's certainly got more options to alter the build if you wanted.
If you decide to build a D36 I have a housing, a rear cover but no carrier presently. I might have one set of pinions and washers. Pay the shipping & $50 for the housing and rear cover if you want to start collecting.
The rear doesn't care if the launch is from a traffic light or a race track, when it decides to retire it will quit.
Last edited by WVZR-1; Aug 29, 2015 at 05:52 PM.
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Drifting
Joined: Jul 2009
Posts: 1,257
Likes: 98
From: Ashland PA
2021 C4 of the Year - Modified Finalist
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
I believe the OP learned all he needed about them from this thread earlier:
https://www.corvetteforum.com/forums...ts-online.html
Thread Starter
Racer
Joined: Nov 2013
Posts: 338
Likes: 8
From: South NewJersey
I guess a good question would be. Is the HD Dana 36 they claim to be able to sell a reality ? or is it just part of there "scam"? allegedly
could I give a local shop the same specs? If I knew exactly what they are?
could I give a local shop the same specs? If I knew exactly what they are?
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
I suspect that this is "their game" - there were two D36 builds and I maybe should have mentioned this earlier in the thread and didn't think about it at the time. You never mentioned the year of the car (that I saw) BUT your user ID hints that it's likely an '84 so yours could very well be maybe a "lesser" build.
What year is the car and is it the original rear?
My guess is that they're calling an HD the second and the build that was used through the end of production.
Thread Starter
Racer
Joined: Nov 2013
Posts: 338
Likes: 8
From: South NewJersey
Yes it is the earlier model. When I spoke to the guy at that website he said they did something in addition to being the later model that made it stronger- more durable.
That's why I made my original post prior to this one . From what I can recall they added material somewhere to make it more like the 44.
P.S. I know the 44 is totally a larger rear.
That's why I made my original post prior to this one . From what I can recall they added material somewhere to make it more like the 44.
P.S. I know the 44 is totally a larger rear.
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
Yes it is the earlier model. When I spoke to the guy at that website he said they did something in addition to being the later model that made it stronger- more durable.
That's why I made my original post prior to this one . From what I can recall they added material somewhere to make it more like the 44.
P.S. I know the 44 is totally a larger rear.
That's why I made my original post prior to this one . From what I can recall they added material somewhere to make it more like the 44.
P.S. I know the 44 is totally a larger rear.
Do you know for a fact that you have the earlier build? Have you actually confirmed the casting number from the original carrier?
Drifting
Joined: Jul 2009
Posts: 1,257
Likes: 98
From: Ashland PA
2021 C4 of the Year - Modified Finalist
I believe the OP learned all he needed about them from this thread earlier:
https://www.corvetteforum.com/forums...ts-online.html
https://www.corvetteforum.com/forums...ts-online.html
Drifting
Joined: Oct 2004
Posts: 1,477
Likes: 80
From: Hawaii
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 113
From: Michigan
What place are you talking about making your dana 36 HD? I know zip sells a HD cover that adds cap supports and you can get the whole diff too if you want. If it's not zip I'd at least compare prices http://www.zip-corvette.com/84-96-c4...ferential.html
Last edited by BOOT77; Aug 31, 2015 at 10:40 PM.
Melting Slicks
Joined: Jan 2008
Posts: 2,054
Likes: 120
From: AZ
My early-design D36 broke and was replaced with a later, stronger cased version plus cyro-treating.
We all want max acceleration but I found the 3.73 too high a ratio for my normal driving. It also afforded less strength, according to the excellent RE shop, unless carefully selecting the gear set.
With the .50 (6th) ZF, the 3.54 is close to perfect; with the 4+3, I would've chosen a 3.36 or returned to the stock 3.07.
Having bought from and met Seeparts, I'll vouch for him.
