suspension measurement 1st gen
 

i am trying to figure out what size shocks i need to my setup. Can anyone with a 67-69 f-body and a 3" drop measure from the front hub center to the lower fender (12 o'clock position).

this way i can raise my hub to that mark and measure what i have between the shock mounts to get me in the ball park.

A more accurate way to figure this out would be to lower the car until the rocker is at the height you want, then put the spindle at the correct height from the ground. Spindle height should match your rolling radius.

A 3" drop is very subjective. Most people do not start with their cars at stock height as they will have settled over time. Springs compress, fenders sag, different numbers of shims are used to get panel alignment, etc.

I agree with you, but i don't have any wheels yet to be able to do that.

I was looking for the measurement so i can make some dummy shocks (out of metal bar) to simulate where the upper control arm will actually be at or ball park area at least. I am about to build my headers and trying to keep the inner fender but they may need to go or be cut near the upper control arm.

I have a tall deck BBC and going twin turbo with some large frame turbos so space is a premium right now (this is more street/strip car) rather than 10lbs of potato i have about 30lbs trying to go into a 5lb bag

If you go to tirerack.com, or a similar site, you should be able to use their tire size calculators to figure out the height of your tire. On a street/strip car with a skinny front tire the rolling radius is typically D divided by 2, minus .5-1.0". The taller and thinner sidewall of a drag tire will have more flex than a low profile, stiff wall handling tire.

i know the front tire will be a 25.7" and backs will be 28" (drag radial).

Maybe i am having a brain fart here but without having wheels to put on the car, and the car in the air how will those numbers help me get the front in the general area?

My rear setup isn't an adjustable ride height and without weight on it i can't tell how much compression i will have to see what the actual rocker to ground measurement is. The rear was designed around a 3" drop but is softer so will probably compress more than normal at full weight.

My idea was to try to find someone with a DSE or TVS system with 3" drop and use that measurement to get the spindles is the area of where they will actually be and when fabricating give myself some wiggle room for the downpipe to pass by without interfering.

I know you guys do this stuff all day long so i am just not following you at this point on how to go about it your way, can you explain?

I'm probably not doing a very good job of explaining this in print so give me a call.