I actually called them today. I agree that the price is certainly the best that I have seen. I have been getting my list together, so far this is what I have come up with:
1. HD Read End Cover $85 - Muskegon Brake
2. 3" Half Shafts with spicer U-joints $150 - Ft. Wayne Clutch
3. Spicer U-joints for Driveshaft $40
4. HD Side yokes $210 -Muskegon Brake
5. Aluminum crossmember reinforcing kit $35 -VBP
6. 300lb 7 Leaf Steel Spring $90 -Muskegon Brake

So far that takes up $610 of my $1000 budget. So I have another $400 to put me toward my goal.

 

300 lbs rear spring is wimpy. You really need 360 or more and a good set of gas shocks.

I always had problems with the stock posi units. The cross pin would elongate the hole in the posi case and at the hit of the throttle I'd hear bad crunching noises. The posi case would be cracked and the pin would be wedged inside. The only cure is the best posi units.

 

If your bushings are OK I would dump the money on the right spindle and do away with a possible nasty. This should still leave you gas money.

If not- a dual mount spring will eat the rest and then some. You may or may not need it though. You can adjust the ride height and spring rate with it plus put C5 rims on and not worry about losing the sway bar.

1/2 of a sidepipe system

 

Techno - I've got new poly bushing throughout the rear, so I should be ok there.
I'm thinking I might get the TRW composite spring from Muskegon. It's $279. How harsh will the ride be with the 355lb spring? Would I be able to eliminate the rear sway bar with the stiffer spring?

*To give an update on my $1000 budget:*

1. HD Read End Cover $85 - Muskegon Brake
2. 3" Half Shafts with spicer U-joints $150 - Ft. Wayne Clutch
3. Spicer U-joints for Driveshaft $40 - Ebay
4. Tom's KA inner axles $285 - Tom's Diff.
5. Aluminum crossmember reinforcing kit $35 - VBP
6. 355lb TRW Composite Spring $279 - Muskegon Brake
7. Tom's KA outer axles $ 210 - Tom's Diff.

This puts me over budget by $84, but I think this is about the cheapest I can do it. If anybody knows of any cheaper prices on the items I have found please post them. I am trying to put this together as a future reference for others who start down the slippery slope that I am headed down

 

OK, well, there it is. I think this addresses MOST, not ALL of the major weaknesses with the IRS. I know that this will not be bulletproof, but for a car that will see very few 1/4 miles passes, and that will not be running slicks, I think it should hold together for awhile at least. Any additional thoughts? Anything you guys would change given the money alotted?

 

You don't have to put on the HD cover just yet. Wait till it cracks first! Really if you have everything correct and tight with better springs ..... smart struts, and poly bushings you don't get the problems of an old sloppy vette.

Also the later vettes like my 79 had just larger tubes. They were pretty tough also. It wasn't untill I started getting crazy with a a 3800 stall tranny and bigger slicks with a line lock that I had one fail. you might save on just the later big tubes.

I also had the rear swing arms stainless steel shimmed for NO, NONE, ZERO toe in. I figured out that the factory toe is really there for the self correcting factors for inept drivers. What it also causes is severe loading when you have big tires because of the constant factory set toe in thrust.

 

I guess I could take that same approach to the whole rear end and just let the good times roll, LOL. Well I figure that the cover is only 85 clams, and since I will have the cover off anyways when I do the inner axles, I figure it is good insurance. Gkull what are your thoughts about the spring I have selected?

 

Get a pair of these...


http://www.dennysdriveshaft.com/html...dent_rear.html

The Nitrous Ready ones should last a long time.

 

just my $.02 , I did all my work myself. went with spicer u-joints,pulled out all the components and after a through cleaning had parts ceramic coated(cost around $350.00 ,half shafts diff backing plate,side yokes, and brake dust cover.) after having clean new looking parts I took the side yokes to a "reputbable" shop to be rebuilt with new bearings and seals (cost anoughter $150.00) had them rebuilt the diff for anoughter$150.00) I did take in all the parts that I had already got from ecklers,bearings 4 both diff and yokes,new carbon fibor posi clutchs 4 diff with heavier Lb. springs,.I already had purchased the HD perf. suspension package from ecklers, that included the Blisten shocks and glass spring. (about $1100.00 ) so for the rear suspension Im guessing around $2000.00--$2500.00. Im going to do the Engine swap this fall (A ZZ383)with a 200-R4 trany thats built by overdrives.the car rides like its on rails now, and the WoW factor is great, best swap for a C-3 IMO.
you can spend all of the budget that I had having someone else do the install or return the diff. and side yokes alone, but you still wont have that show quality look that Ive been able to get . I am not a mechnic , just handy with hand tools, so this can be done over time, it took me 3 months for the front and anoughter 3 for the rear.
go slow and plan for a time of the year that yr not expecting to drive the car much..
good luck,
save the wave. Chuck-75

 

I'd give 355 inch pound a try and see how you like it. I also have a rear 3/4 sway. I can't tell you if it's good or bad to have a sway bar. To many other factors like wheel and tire width. I have @ 24 inch of 35 series of rear tires grabbing the road.

I can tell you that I've never experienced wheel hop in over 100,000 street and racing miles since I did the Mods.

The cover in truth might never break at least in the later wider 2.5 inch spring models. The weight is spread out more. The drain plug idea is nice.

 

Just some FYI. If you have the patience you can get some of the parts you are looking for new on Ebay cheaper. HD rear cover $50-60. It will say Muskegeon right on it.

 

Just some FYI. If you have the patience you can get some of the parts you are looking for new on Ebay cheaper. HD rear cover $50-60. It will say Muskegeon right on it. Basically it will give you free shipping with the savings. On a tight budget every $20 saved=more/better parts.

 

Thanks! I will watch on Ebay for one.

 

Be aware the HD covers are very good, I've used several but they all had the center to center bolt pattern off a few thousands causing the 4 spring mount bolts to hit the spring leafs. I had to radius the spring for clearence using all those covers. I'll have a new radiused spring at Carlisle next week, if you go stop by and I'll show you.

Gary

 

Thanks for the tip, Gary. I have been meaning to tell you that you did a great job on my steering box. The steering feels smooth as silk now, and the finish looks great as well. Kudos to you.

 

It's the price of having power. I have a good time with only 427 ci. Last night i went out and entered a car show. On the way home I spanked a hot 2005 Cobra and noticed some IRS area noise on the way home.

Tonight I jacked it up to see what's wrong and both of the nice U-Joints on the left half shaft are hoosed up. So my morning will be filled with the 10 ton press getting them out

What ever you end up with it doesn't ever cure it's self. Always stop right away and check.

 

no slicks, not drag racing each weekend,less than 400hp,,i'd do the HD replacement parts and make sure it's correct my vote

 

Oh well, if you delivered a proper beating to him then I say that it was money well spent! Alot of people underestimate our cars, especially the later year C3's.

 

Thanks Grant,
I'm glad you like my work and your car "feels" like a vette again! If you have any questions I may be able to help with let me know.



Gary