[J-Garden]

I'm about to purchase a 4 Link frame rail Kit from competition engineering. Just wondering what you guys thought the best set up would be for the spring rate. Going on a 71 Nova. Car will see the track ocassionaly(2-3 times a year) I plan on mounting the shocks behind the axle. I don't have the indiviual car scales to measure at each tire, and I'm still waiting on Dave Morgans book: Door Slammers that I just ordered. Thought I could get some helpful hints and anwsers in the meantime.

BB 454, 4 speed
1500 lbs at the rear
Total vehicle weight is 3520

[ericnova72]

I would say 130 lbs springs.

[406 bug]

I would think 175 min. but call comp engineering or the manuf. you are getting the coil over form and they will be able to give you a rate. Other factor to consider is if you plan a straight up or angle on you coil over installation.

[ericnova72]

The chart at Chassis Engineering puts you right in between 130 lbs and 150 lbs. If this is a drag car then I still say 130 lbs, if the street then maybe the 150's. We have 130's on the rear of a 4-linked 1967 El Camino at 3050lbs total car weight and they are borderline too stiff for drag use but the car does get street driven. Car runs in the 10's quarter mile on 315/65-15 MT Drag Radials.

[J-Garden]

Originally Posted by ericnova72

The chart at Chassis Engineering puts you right in between 130 lbs and 150 lbs. If this is a drag car then I still say 130 lbs, if the street then maybe the 150's. We have 130's on the rear of a 4-linked 1967 El Camino at 3050lbs total car weight and they are borderline too stiff for drag use but the car does get street driven. Car runs in the 10's quarter mile on 315/65-15 MT Drag Radials.

What width did you go with 24, 26 or 28?

[ericnova72]

Originally Posted by J-Garden

What width did you go with 24, 26 or 28?

We built are own 2x3" tube frame in the rear because a kit frame was going to come up above the bed floor where it goes over the axle. Frame width was 32" outside to outside. The wider you can keep the frame (allowing for tire fit and sidewall flex) the more stable the car will be. I prefer to custom build my frame rails to get a more "personal" fit to the car, rather than a fits all kit. Not knocking the kits though, they are fine performance-wise.

We're running the MT Drag radial that matches up to a 30x 12.5" slick on a 10" wheel, with 5" backspace. Car was built with room between the rails and tubs to allow for a 12" rim with 6.5-7" backspace and a 31x 14.5 tire if we wanted to go bigger.

Get your wheels and tires first, so that you can set them under the car once you have cut away the wheelwells and trunk floor areas and measure off of them, DON'T rely on published tire size listings as they ARE NOT correct.

Good luck, measure 3+ times and cut once, and have fun . I enjoy building them almost as much as driving them!

[J-Garden]

What would be a good Front Spring rate to go with?

[ericnova72]

Factory style spring for the stock subframe or a coilover conversion??

[J-Garden]

Coilover conversion

[ericnova72]

I'd consult the company you plan to buy the coilovers from and tell them how you plan to use them - street/strip, drag, pro touring, cruising, etc.

[68NovaSS]

In my '68 Nova back half, 4-link car I run 150# springs on Alston QA's. It's a little rough on the street.

[J-Garden]

What do you run on the front?

[68NovaSS]

New big block coils, work good with the additional weight.