I have a 73 big block convert. and i just rebuilt the rear suspension and differential. I used Vansteel's Hypercoil 330 lb spring. With 8 inch bolts it ended up sitting 2 1/2 inches to high. Vansteel seemed shocked that I had this problem and offered to #1 send me a new 330 lb spring in the unlikely event that mine was mislabeled and was really a 360. #2 Send me 10 inch bolts. #3 Send me a 200 lb spring.
I choose #2 because it involved the least amount of work on my part. I did not want to have to go through taking the exhaust off again.
I put the 10 inch bolts on and it brought the ride height down to within an inch of where it is suppose to be. The bolts are not close to the tires. I knew I might have a problem with them bottoming out in the event of a flat so I let the air out of the rear tires and the bolt was within an 1/8 of an inch from the ground. I did not have the nuts lowered all the way so I can cut about a half inch off them to give me more clearance.
My questions are, Is a half inch from the ground still too close? Should I go with the 200 lb spring and the 8 inch bolts and give up the handling benefits of the 330? Or should I go with another spring manufacturer (assuming I can have the best of both worlds if I do, the correct ride height and no bolt clearance issues)?
Any suggestions/advice would be appreciated.
Thanks

 

I would go with another spring manufacturer. Spring rate shouldn't affect ride height. VBP seems to have this figured out.

 

I agree,
Get VB&P 330 spring. I have it on my 75 and the height and ride is just right.
Good Luck
Steve

 

VB&P know their stuff when it comes to those monosprings

 

i took before hand measurements for my rear end. from the ground to the peak of the fender lip, it was 28 /1/2 inches. with a complete rear end rebuild, all new bushings, new shocks, and the 330lbs vbp mono spring and 8 inch bolts, its 28 3/4, with maybe 3-4 threads left on the bolt.

downside being that if i ever have a flat, ill still be digging into the ground with the 8" ones and stock 15" rallies.

 

Due to the way VBP manufactures their springs, they can dial in on a rate to work just right for your Corvette. They also have different arch styles available.

For a 73 big block and for a stock ride, a touring ride quality, they would recommend a 330# rear spring. The spring rate range for a VBP 330 is about 320 to 345#/inch.

If you wanted more of a performance feel for some light racing, you could opt to go with their 360# rear spring. This has a rate range of 345 to 380#/inch. This spring also has a little bit of a lower arch style and you would sit a little lower than stock.

They can put you in a low or high end or just in the middle of the rate range. Once it is determined how you want your ride to feel, where you want the ride height to sit and how you will be driving your Corvette, then a spring rate can be picked out for you. They have all kinds of rates on the shelf or can make up a spring at a requested rate for you. Because of the way they manufacture their springs, you have the option of choosing from a variety of rates. The other manufacturers pretty much have two rates and that is it.

The 8" bolts would be the ones to use. The VBP bolts have more threading and are longer than stock, this gives you about 2" of additional play to set the ride height just where you want it. They also have 10" bolts, but they are used more for the C-4 generation. The 8" bolts with the proper rate and arch style would be the correct set-up for a C-2/C-3 Corvette.

If you have any questions or would like some assistance, please do not hesitate to contact me or you can call Steve and/or Gary in their tech department to help you out. You can private message me or email directly to pattiesattic@tampabay.rr.com or call them toll free at 1-800-237-9991.

Pattie