68/70Vette

I needed to seperate the frame/body to mainly install new gas lines. I have a convertible, and to lift the body, it appears you need to remove the doors and replace the doors with rigid brace bars to support the rear of the body during a lift. To replace the gas lines you only to lift the body up 10 inches (?). It looked to me to be easier to just drop the frame if this was all the lift I needed.
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I started with the car sitting on its front wheels and the rear supported with a floor jack (rear wheels removed). I removed the #1, #2, and #4 body mount bolts and also I removed the radiator support to front crossmember bolts. Next I replaced the radiator support/front crossmember bolts with bolts about 8 inches long. This would allow the body/frame seperation at the radiator support but would prevent the body from moving sideways when I finally did the frame/body reattachment.

Next I first jacked the entire car up until the front wheels were about 6 inches off of the ground. (Two floor jacks) Then I began placing supports between the body and the ground. The idea was to support the body. For supports I used sections of 4" by 4" and 2" by 4" lumber. Also I bought 2000 lb bottle jacks from Sears (3 of them for $14). I built wooded supports for the tip of the nose, the rear storage compartment (wood supports for the compartment floor to ground). Also 4" by 4" supports across the floor of the passenger compartment to ground (actually after placing a wood beam under the compartment floor) and supporting this beam with a floor jack.

Now with the body supported, I removed the #3 body mount bolts and lowered the frame. The front wheels are supporting the frame in the front, and the rear of the frame is being supported at the differential with a floor jack. I have about 10 inches of frame seperation at the rear and about 6 inches at the front.

With this seperation, it was easy to replace the gas lines. I replaced the lines with stainless steel repro lines. (I've already installed repro ss brake lines). The gas tank was removed before the frame seperation. I have a new tank and plan to install it before remating the frame/body. Gas tank installation should be a lot easier with more room to angle the tank into the space between the frame and body. This amount of frame seperation is also sufficient to clean and paint the top of the frame under the bird cage.

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Lessons Learned. I had to increase the amount of structural support under the passenger compartment floor. The body is primarily supported at this location. It probably weighs about 1000 pounds and this is a lot of weight for the fiberglass floor to support. Also...shim control!! Some shims remained attached to the body, and later fell to the ground. Also other shims fell to the ground. I was eventually able to sort out where the shims came from. Next time I'll be more watchful and drop the frame slower. Some extra eyes would be a good idea.

Once you've removed your engine/transmission, dropping the frame is not all that hard, just a little tedious unbolting all the bumper supports. You have to seperate the master cylinder/brake lines so you'll have a brake bleed task ahead.

Stewart's74

I replaced my fuel and brake lines without lifting the body.
If I had the space...and the time I would have preferred to do a complete body off resto

68/70Vette

I don't think I could have replaced the gas lines with the body on. I used stainless steel brake lines and they don't bend very well. However, there's a little fiberglass "tab" on the body that covers the #3 body mount. If I had cut this off, I think then I could have got the lines in by just lifting the left side of the car, perhaps, an inch. If this would have worked, it wouldn't not required the MC/brake lines to be seperated.

Oh, another thing, by lifting the body up perhaps 10", I could then remove and install the fuel line clamps. I had adequate room to remove and replace these parts. If I didn't have this high of a body lift, I wouldn't have been able to do this.

My drop-the-frame technique doesn't really require any extra space. As long as you have room to maneuver a floor jack handle sticking out from under the car, you're good to go. Time is another matter!!!