Rear Ride height
 

I recently swapped in 4.11 gears and at the same time moved my rear tires in a half inch, which required a shortened spring. The new spring is 440 lbs, the old was 360, so naturally the rear now sits higher.... I haven't topped off the gas tank or driven it much at all since the work was done, and now that it's snowing......I have time to gather parts for spring. Right now I have the 8 inch bolts, adjusted almost all the way down, and am wanting to drop the rear another half inch, maybe a little more, so ideally a nine inch bolt should work. In looking for that,......like hunting for skipe,.....no can find. Alternate solution C-4, C-x 10 inch bolts, then cut the unneeded thread off.

Anybody know of another option? I tried Fastenal, McMasters,....etc. Forget the big box stores...I don't trust picture hangers you get from there.

https://cimg5.ibsrv.net/gimg/www.cor...83aa07727.jpeg
This is just a mock up I did to get an accurate measurement prior to ordering the custom Van Steel spring.

C-4 bolts are the best bet. Call Zip Corvette down in VA and you can probably get them in 1-2 days.

since your picture is a mock up, with the real spring installed and the suspension settled, what angle are the half shafts sitting at, level to the ground, inside higher or outside higher, and if not level what is the difference in height inner to outter?

The mock up has the half shafts about level and while it was in that position I measured the tire clearance to the fender lip. I had 1 1/2 inches with it in the air. Once on the ground, I have right at 2 inches, so about 1/2 inch high. My hope is to lower the car so I'll get my 1 1/2 inch clearance back, the half shafts fairly level. Problem is the 8 inch bolts don't quite make it.

Once the ride height is set I'll tinker with the bump stop height so under heavy throttle they limit the squat...….295 55 15 drag radials and 4.11 gears...….going to squat for sure.

Are you still looking for bolts?

I got some from Ecklers that were 10"grade 8 bolts. They seem to be good quality. I ended up cutting mine off after height adjustment. Probably ended up being 9"after cutting.

Craig

Yes I am still looking. I did reach out to Zip since they're close, but haven't heard back from them yet.

Just remember this bolt has 1/4 of the car's weight hanging from it. Hanging from the nut. The threads. You wanna try home depot bolt for a mock-up? Or threaded rod? Don't. Drive. It.

Are you sure that by lowering the spring ends a little lower with even longer bolts that you won't be dropping the ends past/lower than the wheel rim when on the ground? If you do and have a tire blowout, that will be rather dangerous.

I had a thought about that too. What if I install the bolt upside down, so the head of the bolt is down, and the threaded part and nut is at the top. Would that help? Also unless the tire is completely off my wheel, I think the little bit I'm trying to extend the bolt wouldn't hang too low anyway. I'm looking to extend maybe 1/2 to 3/4 inch, that's it.

To tell you the truth, I never heard of anyone doing that, but it may work. Not sure if you will have enough room on top to make adjustments easy, you will have to see. I personally just don't like the idea of having the bolts down so far, but that's just me. It can be a recipe for disaster.

I was told many. many years ago the proper rear ride height was when the halfshafts were parallel to the ground with half tank of fuel and driver weight. And to also lower the inner mounting of the strut rods so they too, are parallel to the ground.

The half shaft angle is something that is mentioned from time to time on here, but with everyone putting on big wheels and lowering the car to look right, it seems to have been disregarded as if it didn't make a difference. My 406 puts down a ton of power, and so my concern is more of a durability factor than looks. I had my Dana 44 cryo treated too just for an added strength factor, even if it's minor. The way I look at the half shaft angle is that if the half shaft is parallel, then the 1350 universals will be at their strongest position. Under full throttle, if I limit squat, they will still be fairly close to max strength.

Sounds reasonable to me.

That is kinda dumb to by C-4 bolts or stuff from one of the corvette vendors! Don't you have local nut and bolt places? I just go down to a store like this one just 5 minutes away and I can get any size or length in 1/2 inch increments grade 8 with Nylock nuts for a few bucks each.

https://www.re-fastener.com/

Oh, I don't know where your rear spring was made. but it has been my experience that as the pound rating went up I needed shorter and shorter bolts because the stronger springs had less arch. My latest 500+ pound is clear down to 5 1/2 inch end bolts

Amazon:) Just look up what ever you need!

gkull,

You have no idea how much I scourer the internet to purchase items I know I'd never find locally. I used to waste my Saturdays driving to every parts store I could find and end up empty handed. Summit Racing became my go to for almost everything.
There is one specialty place near me that I have used. "Totally Stainless", and I've purchased quite a bit from them. The last time I went there.....they didn't have the size I needed, and so I ended up ordering online.

My 440 lb composite spring was made by Van Steel, as VB&P is no more. The old spring was VB's 360 lb, and I was using 8 inch bolts. On the floor placed on top of each other the springs looked very similar in arch, except the 440 was shorter per my request. This pic was taken at Van Steels shop when we were trying to coordinate my new spring. I sent him my old spring marked where I thought I needed the new spring shortened to. The difference in ride height with the bolts adjusted about the same as originally is only 1/2 inch,likely due to the increased spring rate....but the 8 inch bolts just won't make it. Needed to go a bit longer.

https://cimg9.ibsrv.net/gimg/www.cor...b1795e04d9.jpg


I don't mind having to purchase online if I must. But what pisses me off is paying $10 shipping for a $2 part I can't get locally.

I'm fortunate to live in a modest size city with most everything you could need locally and amazon prime is great with "FREE" shipping for only $99 a year. I've worked out of state is small towns that only have an auto parts store like NAPA and it drives me nuts having to order stuff and get it days later.

this is my removed spring bolt from a VB&P 420# which I bought at the nut and bolt store.

https://i.postimg.cc/tggD4j2c/Spring-bolt.jpg