I can't tell you all my worries with this C4 IRS. LOL's. But I think I can...I think I can.

Who on here has done the C4 IRS set-up on thier street rods? I did a search in the photo gallery but I'm still having trouble. I PM'd 32 Chevy Vette. Doesnt look like he's been on in a while.

What angle do I need to set the frame braket at for the dogbones? 55 degrees looks like it will still allow plenty of suspension travel (3.5" or so).

How narrow have you guys gone? I was thinking about making a 1" spacer between the differential and the cover, which would move the batwing back 1" and allow narrowing the rearend 6" over-all. I would still have to hog out a small portion of the hubs (knuckles) to clear the batwing....but not much with the spacer added.

I could really use some help here. I'm about to ditch it and opt for a nine inch. I dont usually give up this easy...but man my head hurts.

Dave

stovebolter, hang in there. there was a post in the C1-C2 section of corvette forum about a year ago adapting the C4 IRS with pics off all the attachment points, angles, the way all the brackets were made with dementions imposed and detailed pics. i spent an hour searching the archives and couldn't find it. i will post tomorrow and ask "where are those pics. they are a great bunch of guys, i'm sure somebody will know, and if so i will post a link.

Thanks techron! Is it the Corvette Forum....Digital Corvettes Forum....Corvettemechanic Forum. I'd be happy to dig to.

I've subscribed to 4 Corvette forums to find this information. Still havent found it yet though. Still trying. Thanks....seriously...Thanks!

Dave

stovebolter, it was corvette forum, C1-C2 section. it was about adapting the C4 IRS on a C2 frame which looks similar to the pics of your frame. i will ask over there right now.

Thanks, I've subscribed but still cant post on the site till admin gives me rights. I'm searching thier site though.

Thanks,
Dave

don't worry, i posted the question for you in C1/C2 section, just lurk and wait for an answer. people are looking but no responses yet.

http://forums.corvetteforum.com/sho...d.php?t=1980835

Thanks techron! I'll keep my eyes peeled to that thread. I tried to subscribe but I still dont have admin rights to do anything but look right now. I'm starting to think I may have been duped anyway.....I've been looking at the differences of the Dana 36 and the 44. The fella I bought mine from listed it as a Dana 44. Well after looking at this site.....http://temp.corvetteforum.net/c4/vader86/rearaxle.html ......I have a sick feeling I now am an owner of a D36 instead of a D44. I'm not sure. I'll have to wait till I get home and run the numbers.

Again, Thanks!
Dave

No need to run the numbers. Just look at the pictures on the link you posted from Vader's site and count the number of bolts that attach the bat-wing to the diff. The 36 has one additional bolt compared to the 44.
If you bought it right, the 36 should be fine for a street car unless you're making a lot of power and/or doing frequent launches with slicks, drag radials or other gummy tires. But if you paid a 44 price and got a 36, then you deserve to be understandably pissed. The 44 diff. and bat-wing is worth many hundreds more than it's 36 counterpart.

I almost hate to admit it.....everyone's going to think I'm an idiot....but when I'm wrong, I'm wrong. All I had to do was look at my own pictures on this thread and see it was a 44. Multiple ribs on top of chunk....whereas the 36 has one visible rib. Where is my sign folks? LOL's. Shwew! I was getting worried. I could have sworn last night while I was doing the good ole string and plumb bob measurements that I used one single rib to check center....but again.....I was wrong.


I got a response back from Gene Robb on the Dana custom differential cover. It is 27". A whole 10.5" narrower, but he said it is for a Viper. I guess I thought that the Viper's used the same basic Dana 44 as the Corvette's with the exception of front mounting points? Can anyone clarify? If I can use the Viper cover for my Dana 44 my problems are solved.

Thanks,
Dave
Dave

Well....I've decided to ditch the idea. I've decided I'm going to lose too much bed space. I can do it...but I'll have to raise the floor of the bed to make it work. I've decided to chock this up to a painful waste of money....and will give it to my dad for his 41 Ford Coupe. It has a much wider frame and losing a little space in the trunk won't matter as much. Thanks everyone though. Dad is tickled with my mistake!

Dave

I'll bet he is!

Hi! just got back from florida and got your message i hope i can get to you before you cut any thing. I did not do any thing to my rear end except change over to coil overs.looking at your photos. I don't think its as bad as you are making it to be. You can do it! But i know where you are coming from i also had a lot of sleepless nites. First is mark the frame as to where you want your axles this will tell you where you must put your bat wing. I used 3x3 sq. tube with 180-200ths wall, I cut out one side for my bat wing to go in leave 2" above your cut. The tube should go from the top of the frame down to 4"below the frame. i rounded the bottom of the cutouts and capped the top.I then drilled the holes for the bat wing i put in 3 holes 1" apart so if i needed to go up or down i could. You will need to grind the little nubs off the end of the bat wings.I think progressive automive makes a kit, check on line you can see how they done it.I did not use the 4 bar set up i used long hair pins. If you didn't give up let me know and i will get some photos and sum angles for you from my friends truck. Look in my gallery page 8 and 9 go for it will do it.

Ah ha! Found you. Hope you enjoyed the vacation! I had ditched the idea thinking the frame was just too wide for my batwing. The frame is 41" outside to outside at the center point for the axle. But I changed my mind again. I found a fella just 5 miles down the road from me that is just tickled to help narrow the batwing. We're cutting 5" off of each side for an eye to eye width of 27.5 and we'll add a plate on both sides of the wing to give a little extra support. I'm told its made of 6010 and should be able to tig the thing. I'll open the area around the rear like Progressive does and box it. As far as angles...I'm still getting mixed responses about the correct angle for the half shafts at ride height with weight on the springs at rest. I know I'll figure this thing out. Have to. Any help from you would be much appreciated.

Thanks,
Dave

Stovebolter I hope i get to you, before you cut the bat wing. If you haven't DON'T there is no reason to do this, as the bat wing go's under frame your frame is 41"on the out side the bat wing is 40 1/2"to the out side of the box that i told you make from the 3"x3. Box in the frame from cross member,to the center of the axle or more now notch this box from the out side in the width of the frame and down the depth of the frame. Make sure you drill the holes and cap the top before you cut the notch. After the boxers are done set them up on the bat wing with the bolts. With the frame in the notch where you want it to go then tack it don't weld it. Now you have to make up the pads. For your dog bones they have a 60 deg. angel to them.I did take photos but have not down loaded them yet. I had you drill 3 holes so if you don't like the hight you will have 3" to go up or down. Let me know how you made out and i will get the photos to you. Slow down, Do it right, Do it once!

Too late. I just called him to see where he was on it and he said he has the ends cut and mocked up for welding. I'm having it narrowed a total of 10" overall. I wanted to set it up like your talking about, but, I have to narrow each side 3.5" to fit my wheels. Which would mean hogging out the hubs if I left the batwing as is. (I was going to have him make a sort of cage or spacer and space the cover/batwing back 1" so the ends would clear any vital parts but I thought shortening the batwing would be less fabrication. I really didnt feel comforable grinding on the hubs. So....do you really think I've messed up? I've seen some of his work and he seems to really know what he's doing.

Thanks,
Dave