Technical Rear ladder bars

I am installing rear ladder bars on my Model A frame,do you guys install them so they are level to the front to back when they are at ride height,they are pete and jakes. Thanks. DDDenny please chime in.It is a model A roadster, frankland quickchange,SBC ,t 10 4 speed.

 

Hey SD
And not just any sbc either!

 

For a fairly neutral street ride, make the lower bar level at ride height.

You're not on a drag strip, or a road race course. Level is good.

 

As Gimpy states, the ladder bars need to point up or be horizontal to be geometrically correct and give you anti-squat with the correct amount of pinion angle at ride height. Pointing them down will cause the car to squat under load which will in turn can cause the rear tyres to easily unload. The pinion will point down. The front pivot points need to correspond horizontally with centreline of housing at ride height.
With anti-squat built in and bars pointing up at the front up, the wheels have a tendency to turn the axle in the opposite direction. This motion causes the bars to push the car up.
With them pointing down the opposite occurs and the rear drops.
Race cars can have 1-2 degree down angle

 

Lower bar not upper?,what happens with upper bar level.This is a street car but it does have a aluminum SBC 427.

 

Are you talking the top bars need to point do,how much

 

The front pivot points need to correspond horizontally with centreline of housing at ride height so the top bar, if installed similar to above, will be horizontal (Parallel) to ground, lower bar will point up as it mounts lower. They need to taper in at the front pivot point. This is a 32 setup, those more experienced than me will chime in with more specifics.
http://www.srbymichael.com/index.cfm?ptype=results&category_id=931&mode=cat&start=49
https://www.hotrod.com/articles/install-ladder-bars-ford-9-inch/

 

The front pivot point needs to be slightly lower than the axle centreline on a street driven vehicle.
This does induce a slightly more amount of squat [which springs overcome]
But the advantage is a more neutral ride because of roll understeer.

 

This.

 

Thank you all

 

Now, about that engine?

 

It is a SBC rodeck 427 aluminum block,brodix heads,roller cam.It has a 4 barrel 3310 on it now,later 2 1/16 hilborns mech injection

 

These at P&J ladder bars on my '32 pickup, hope this helps. HRP

 

Here’s my old Model A, with Pete & Jake rear ladder bars.

 

How far apart were they at the leading end?

 

front is 7 and 3/4 inches I believe

 

Not you, the guy with the photos. Those ladder bars look parallel.

 

The ladder bar kit comes with the front crossmember, with those attachment brackets already welded in place. I no longer own the Model A, but I checked my ‘34 and here’s what I have. My ladder bars are 43” long, including the rear clevice. If your bars are this same length, the setup dimensions will be the same as the ‘34 Ford. The bars mount to the front crossmember, 6” apart. They mount to the rearend 31 1/4” apart (if my eyesight is correctly reading that fraction).

 

They are not parallel. I used the Pete & Jakes crossmember, which determines the angle.

 

Did you see my response to this question? It’s two notes, prior to this one.