1969 BB Ride Height

[Love_69]

Hi,

I have been researching the correct ride height for my '69 Corvette, but the figures I have been seeing suggest that, from factory, the ride height is rather high. Just to be clear, I do not want stock height, I prefer the car to be lower, but not ridiculously low. As a relatively new Corvette owner, I have found that the ride height at the moment is somewhat low underneath. For example, the sump is only 2.75" off the ground! Below are some pictures to illustrate it overall. The block of timber in the pictures is there for scale...it measures: 3.5" x 1 3/8"

The rear ride is okay - especially as the fuel tank is empty!


Front ride height:


Front ride height looks fine to me:


Frame height approx. midway along the frame:


Long angle view:


Sparks will fly off the exhaust on our roads in Oz!!


My next question is what size/specification springs to you guys suggest would rectify this "problem". Remember, there's a 427 under the hood.

[vito]

Here ya go. This is for a 70 but the same information. The important ones are P and Z on the chart. Also remember that the correct tire size is F-70-15



Cheers

Vito

[MaineVette]

Could have sworn I replied to this thread but don't see my reply anywhere... odd

In any case, stock clearance for a 1969 Corvette is about 4.75". I'd go by Vito's attachment showing how a stock setup should be. With your existing clearance I think you'll have issues, I suggest raising it a bit.

[Love_69]

Thanks guys. According to the 1969 Chassis Service Manual...the overall height should be 47.8". Mine measures-in at 46.6" - which is pretty close to factory height.

A work colleague suggested that the sump being so close the ground could be the result of worn engine mounts. Is that a valid suggestion?

[rbryce1]

In my opinion, not a chance.

The difference between your two numbers is 47.8" - 46.6 " = 1.2" or about 1.1/4". The entire stack of rubber in the engine mount is around that thick.

Assuming you have the correct tire size, my best guess would be spring height. Did the big block come in the car? Big block engines weight enough more than small block's that they require beefier springs.

I would look at the possibility that either your front springs are not the right ones or they are possible a little weak, or that it was just how your springs were built.

[Love_69]

It is a matching numbers vehicle, so yes, the big block came with the car. The tyres are 235/60/15 front and rear. Not exactly sure how that measures against the factory spec F70-15 (not sure what "F70" means). It is sounding more like the front springs are either:

1) Tired and need replacing, or
2) Have been replaced with the incorrect height ,but correct load capacity, or
3) Have been replaced with correct height, but incorrect load capacity, or
4) It's something else (hehehe!!)

I guess I won't find out until those springs come out. It's kind of a shame really, as I think the current ride height front and rear is spot-on. Left as-is, I know that I will be cringing every time a depression or slight bump in the road approaches, quickly followed by the temporary suspension of a thing called breathing, as the bump passes under the car! Not exactly the way to enjoy summer cruising in a Vette!

[Love_69]

Here ya go. This is for a 70 but the same information. The important ones are P and Z on the chart. Also remember that the correct tire size is F-70-15



Cheers

Vito

Vito - I measured the "P" value on my car. It comes in at 24 3/4 inches! Much lower that the 27+ inches from the chart. The "R" value measured 27 1/4 inches, so, not far off the mark.

[vito]

The Tires should be F-70-15 which is 26.9 inches tall. Your tire is 26.1 inches, which automatically lowers the car 0.4 inches (10.16mm). Are all tires the same size?

The Z measurement should be around 2.65 incher. If the number is lower then this there is a problem or someone changed something out. This measurement is critical if you want a stock ride height.

The D measurement should be around 2.18 inches. Same thing as above. Also look at the rear spring. That picture shows is relatively flat. The spring on mine has an arc. This measurement is critical if you want a stock ride height.
If someone changed the springs/longer bolts to lower the car the Z or D would be off. From side to the side numbers need to be the same or close.

Cheers

Vito

[MaineVette]

If you get your stock springs out let me know. I have the stock springs from my 71 BB out in the garage and I can measure them so you can compare to what you have. Just let me know.