Can you guys help with my subframe?

[48builder]

Some of you may remember that last year I posted about my wheelbase being too short on my sub-framed '48 Chevy. Here's a link to that thread.

http://www.roddingroundtable.com/forums/viewtopic.php?t=5035&highlight=


I have finally decided to fix it now while the body is off the frame. I'm looking for some info.

Can anybody answer these questions? I am using a '87 Grand Prix front clip.

What should I use as a reference point? It looks like the zerk fitting on the upper ball joint is at the wheel centerline. Or maybe the shock mount? I have all-thread in place of the shock now.

I used the all-thread to set the crossmember at ride height, but have since loosened the nuts. What should the distance from the ground to the crossmember be?

Should the front frame horns be level? I think that is the way they were when I cut the clip off.

Anybody have a post-war Chevy and can provide me with a good measurement to use for the distance from the ground to a reference point on the frame at the cowl? I can use the clearance from the ground to one of the body mounting points. I want the car to be low, but not so low that I scrape all the time. I know Bob K's car sits right. Hopefully he will see this.

I'm not sure how I screwed this up in the first place, but I want it to be right. The body is coming out great, and I want everything to be correct.

Anything else I need to know? The stock wheelbase was 116", I cut 2-3/16 out of the body. I wanted to end up with a wheelbase of 114 -1/2 but only have 113".

Thanks

Walt

[WZ JUNK]

I think the zerk in the lower ball joint would be a better reference.  The upper arm should be the adjustable one and it may not be in its correct place but the bottom one should be right.  Assuming all of your A arm bushings are good and tight.

John

[Charlie Chops 1940]

Maybe look at one of those cars or its clones and see how the lower a-arm is oriented to the ground- level, uphill, downhill. That's the relation ship for the sub. You can build a little rake in by bringing the 48 frame down to the sub, however making them level/square to each other is probably best. Adjust ride heigth with springs after the car is together.

Charlie

[OldSub]

I have a bare '78 g-body frame sitting complete in my shop right now.  If I can measure anything on it for you I'd be happy to.

[48builder]

I have a bare '78 g-body frame sitting complete in my shop right now.  If I can measure anything on it for you I'd be happy to.

I really just need to know if the frame horns in front of the upper control arms are parallel to the ground. Distance from ground to the bottom of the crossmember would be a plus.

Thanks!

[enjenjo]

On the passenger side, the frame horn is parallel, the drivers side may, or may not be depending on the model. The crossmember is usually 6" off the ground on OE applications, but also varies with model. The upper shock mount holes are at axle centerline.

[48builder]

On the passenger side, the frame horn is parallel, the drivers side may, or may not be depending on the model. The crossmember is usually 6" off the ground on OE applications, but also varies with model. The upper shock mount holes are at axle centerline.

Thanks, Frank. That is just what I needed. My friend who is going to do the work came over tonight. Plan is to get it started tomorrow and wrap it up Friday afternoon.

One more thing. You used to have an article in the tech section about subframing a pickup. There was a figure you used to extend the wheelbase so that it did not look funny when the front is lowered. I think it was 5/8". My original wheelbase was 116. I shortened the body 2-3/16". Adding in that fudge factor of 5/8" means that 114-1/2 should be just about right for me. Sound right? I have 113" right now. I think 1-1/2 added on will do the trick.

Walt

[47 ragtop]

My 47 chevy is 7 1/2 inches from the bottom of the frame to the ground measured at the 1st body mount near the cowl. The bottom of the front bumper is 7 inches from the ground. The front tires are 215/70 R14. My car has a CE adjustable front crossmember and the lower control arms are paralell to the ground. My car will scrap the front bumper on curbs or concrete parking blocks. Remember you can adjust ride height with tire diameter as well.

[enjenjo]

That sounds about right, error on the side of too long rather than too short.

[48builder]

My 47 chevy is 7 1/2 inches from the bottom of the frame to the ground measured at the 1st body mount near the cowl. .

Thank you very much for that info. Do you have a pic I could see?

Walt