transam84

I have a line on an 89 corvette IRS.it is complete minus calipers.it came out of an automatic care and the guy said 2:56 ratio.I am very seriously thinking about getting this thing and having it put into my 86 T/A.I personally would not do the fab work,I know of a shop that lives for these types of jobs that I would trust completely,considering the size of the job one would have to.anyway I don't know a whole lot about the corvette IRS's.is this a good one to put in my car or is it a bad one???

Flip 2

iTrader: (1)

Putting in is a WHOLE lotta work. Great thread, from not too long ago, shows all that went into it. I think the thread also covers the subject that follows.
First off, this info is from reading here, but I think correct.
That said; with that ratio the rear is from an automatic car. The six speeds had Dana 44s, which are a good bit stronger than the Danas (36?) on the automatics. The 44s are also a bunch more $$$s.

transam84

How weak is this rear end then? Will it handle at least 500 ft lbs of torq?

Kevin Vandevenne

iTrader: (3)

This is just going from my memory, which isn't the best at times, so if its wrong, hopefully someone can correct me, but the D36 is a stronger diff than what came stock in 3rd gens, but not to the tune of 500ft/lbs. The D44 would be a better choice for that power level. The other factor if i remember right is that with the D36 the inside of the case is fairly small, and you are limited to the size of rear gear you can run.

transam84

Right now my 383 dyno tested 424 ft lbs of torq at the crank.I have on the car now a 9 bolt which has done very well and not having any prob with it,this would just be a really cool mod if this rear would not explode the first time I mash the gas pedal.

transam84

Forgot to mention,I am running a 700r4 so that will reduce some of the torq before it gets to the rear.

Flip 2

iTrader: (1)

Here's the swap thread;
https://www.thirdgen.org/forums/susp...uspension.html
Done right, plus.
Think you want a Dana 44.

FlyDoc

here is my thread for my IRS swap;
https://www.thirdgen.org/forums/susp...e-c4-rear.html
if you go a head with the swap, PM me and I can let your shop know what troubles I had, and how I did the swap and how I would improve the swap.

88fastgta

iTrader: (9)

i actually have a dana 36 corvette irs sitting in my back porch... my dad swapped to a dana 44 in his vette..... it looks like a TON of work to fab and i would never think about doing that swap.... the dana 36 is like the ten bolt for our cars in strength.... over on the corvette forum there are guys who have busted the dana 36 with just mild bolt ons barely breaking the 320whp mark... alot of guys get the much beefier 44 version.....

transam84

Ok now the IRS that I could get has everything but the calipers.so if I buy this setup for $300. Take everything off the 36 would all this stuff simply bolt onto a 44? Or if I had the 36 fitting in the care then when I get a 44 would it just be a simple straight forward swap?

Kevin Vandevenne

iTrader: (3)

I believe one of the main support braces known as the "batwing" is different between the D36 and D44. Not sure on other parts.

83 Crossfire TA

iTrader: (2)

for $300... that's cheap. If it's something you really want to do grab it, you can use it for mock up and even run it till it blows up...

transam84

But if I have the 36 installed and run it till it blows up then is the 44 a direct bolt in or are there diff in mounting locations for some of the brackets??? Kind of like going from a 305 to a 350,its a direct bolt in for the most part BUT this irs setup is very costly to have done if I am stuck with a weak rear end.if.I can not upgrade to a D44.

88fastgta

iTrader: (9)

shoot my dad is trying to sell his dana 36 out of a 95 vette for 300 bux..... complete with brakes...

T/Aperformance

IF I remember correctly the batwing is part of the diff cover. But I maybe wrong. All the mounting points would be the same. For $300 would still be a good buy and if it was me I'd go ahead and install it and when time and money came around I'd change the center section and bat wing diff cover to the dana 44. either way you'd have a slightly better rear end than the stock 9 bolt you have. , Good luck

1MeanZ

iTrader: (9)

The batwing, diff case and C-beam are different between the D36 and D44. The suspension pieces bolt on and the D36 and D44 use the same mounts I'm nearly certain. You could put a D36 in and run it until you find a D44.

If it wasn't so much work I'd put an IRS setup in my GTA. Aside from being much more stable over bumps under cornering and braking on a road course, it rides a lot better on the street than a normal thirdgen. BIGMODS and 92RS(real slow) have both been in my car and commented on how smooth and nice it rides for how well it handles.

That being said, I can do this work myself, which I think is a game changer. You'll have a LOT of money wrapped up in this swap in labor even if you get the parts cheap. I'm not sure the benefits are worth spending all the money you'll spend paying to have the swap done. Maybe I'm wrong or I work too slow. But you can see how involved my build was, it took me from October to April working 7hrs each night of the week and occasionally on weekends to get the swap done and the roll bar installed. I'd say the roll bar was less than 20% of the time spent.

My point is, unless you've got money to waste, think carefully before you drop the money to pay to have it done. The benefits for a purely street car may not justify the cost.

88fastgta

iTrader: (9)

yea if its a fun street car i would just build open the stock design.... my car handles extremely well.... im sure i can make it handle better but i dont autocross or anything like that so i will just be wasting my money...

i would suggest getting the watts link setup for your thirdgen if you want to be handle freak.... its not nearly as challenging as an irs swap' but its a upgrade over the stock design... i thought about getting it myself....

http://www.stranoparts.com/partdetai...D=65&ModelID=9

FlyDoc

1MeanZ is correct, if you would pay someone to do this, it could get very expensive. for swapping from a 36 to a 44 is just the deferential and batwing.
Knowing what I do now I would build a jig off a Vett, it would make it almost 100% easier. with the jig you would have all mounting points in the correct position to each of the other points. and axle center line. so instead of having a flopping reared, fixed mounting points.
Dam hind vision is 20/20.