Model A "Z"

This is my first project starting from scratch and I have a million questions. I'm building a 29 model A 2 door sedan. What is the ideal amount to "Z" the rear of a stock Model A frame to get it to sit right. Is 5" too much? I'm thinking I can run a 40's rear end converted to a drive shaft, using the stock banjo spring. Am I on the right track?

I forgot to add I'll be running fenders.

 

I went 12" with the car channeled 6". I brought the rear crossmember as high as I could til it just about hit the decklid. Here is a pic...

 

http://www.jalopyjournal.com/ubbthreads/showflat.php?Cat=&Number=377371&page=1&view=collapsed&sb=5&o=14&fpart=1

 

Thanks for the Pic, but I forgot to add that I'm running fenders.

 

I may be wrong but fenders will greatly reduce the ammount you can z or channel.

 

How low do you want the frame from the ground? That will help determine how much you will be able to z the frame.

 

I want it as low as I can get it and still be able to drive it.

 

the only way is to mock it up with the wheels and tyres you are going to run tucked up into the fenders, leaving at least two inches clearance (more like three), see where your frame sits, then work out the compressed height of the spring, and sit the x-member at the height needed, then see how much the frame has to kick up to meet it. Its a ***** to work out even with all the parts on hand...if you dont have rear end,spring and rolling stock yet, its super tricky.

 

i might be missing something here, but why does everyone use the stock model A spring and crossmember, even on '32s. doesn't a '32 and later rear spring take up a lot less room in the back? from what i understand, an A spring will clear a quick change rear end, but if you don't have a quick change, what is the point? david

 

Here is a 4 inch Z with 235 rubber, I am now running 285 rubber with no problem. ***** Jag Rearend.

 

Well that photo ****ed lets try that again

 

I like your login name...from one of my favorite movies...

 

I would recommend 18", but it ai't for the norm red, safe hot rod..........

 

Hey HotRodJosh cool car . Do you have any problems with the spring hitting the differencial or other part of the rear axel? Are you using the stock spring ?