Looking for GM front clip insight

[mikec4193]

So I am neck deep in this cobbled up old Plymouth...someone before took the liberty to put a first gen Camaro or late 60's early 70's Nova front clip on it...it was cobbed up mess but it seems with lots of measuring that it in square...but not too sure about the caster on it...

I love the early GM front clips...it is a basic modern style suspension..I have driven straight axle front leaf spring stuff before with the old school steering boxes with big long drag links on them...they are terrible to drive..so that was one of the reasons I grabbed this project...already had coils on the front and Saginaw steering box...

So how critical is caster on these early GM clips??

When I eye ball it...the top of the ball joint appears to be further forward than the lower ball joint...sorta like the set up on a shopping cart front end..

If worse comes to worse I can cut the top A arm mounts off and lean them back until the upper and lower ball joints are lined up...the stock car guys have been cutting these style front ends apart for years...

Any insight from you GM guys would be an awesome thing.

MikeC

 

[Old Iron]

I like to have the upper arm about 1/2" back from the bottom, spindle angle about 3 degrees back at the top.
If it actually is forward of the lower, it will have a darting effect and could tricycle (death wobble).
It can be cut on top of the frame where it and the frame connects and corrected.

 

[mikec4193]

I like to have the upper arm about 1/2" back from the bottom, spindle angle about 3 degrees back at the top.
If it actually is forward of the lower, it will have a darting effect and could tricycle (death wobble).
It can be cut on top of the frame where it and the frame connects and corrected.

Hey Old Iron

Thanks for the reply...I was sorta thinking the same thing but with just doing the eye ball thing...I am going to have to get some help on this setup...this is one scary vehicle I have created...about as hard core as I have ever done before...most of previous projects were more stock-ish kind of builds...

I have a really good front end shop the next town over and he does NYS inspections too...so maybe I will tow it over to their place and get them to try and make it right...I remember back in the day I was oval track racing a 1967 Camaro and I bent the front clip in a wreck and I just cut the bent pieces off and re welded straight pieces off of another clip...and then finished off the season with a really tweaked front clip...young and oh so dumb I was...

 

[Old Iron]

You're welcome
[P[P

 

[DozerII]

I agree with OI you need positive caster, I have a little Amazon digital angle finder like this https://www.amazon.com/Protractor-I...8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

I then have a short piece of 1/2"sq tube cut to length that will fit on the flat machined surface on the upper and lower ball joints that stick past the castle nut. lay the tube on the flat surfaces with the angle finder on it and you can read your caster angle.

 

[MercuryMac]

You've brought something to our attention, Dozer, it's hard to find the angle of the relationship of the ball joints, with your angle finder.
I made a 'template' out of wood that touches the front of the bottom balljoint and the front of the top one and runs vertically, but misses any A-frames or steering apparatus, and the back of the stick is parallel to the ball-joints. I can just put my angle finder on the back of the stick and read the dial. Voila'.