49 Chevy truck steering

Getting to the end of my project and just working getting the alignment dialed. Truck has speedway mustang ii with drop spindles, triangular 4-link setup and rack and pinon with a Ls 4l60e setup. The truck is drive-able but gets a little sketchy at higher speeds.. I’ve had two alignments done now. The most recent shop was able to adjust the rear 4link and make sure it was all dialed but seems to still be real touchy. We did notice the column has a bit of play as well as steering shaft u-joint. (Speedway universal tilt column)
What option should I explore more as for as getting this more stable? I’ve heard people re-valve the rack but supposedly these racks are supposed to handle GM pumps fine.
I’ve attached the alignment specs..with the mustang ii they were only able to get 1 degree on positive caster which is as much as when can get with these control arms

 

Need to ask this in the OT section. We don’t talk about that front end or big wheels on this forum.

 

NEED more Caster. A quick search here shows El Polacko suggesting +2 degrees.
Which doesn't sound like much, but is double what you have now.
The upper A-arm mounts should have been welded in back further.
With the factory lower arms, you can get more Caster real easy.
With the aftermarket stuff, you have a problem.

 

At speed does it want to drift off or wander if you have your hands off the wheel? On a turn does the wheel return to center when you straighten out pretty well on it's own?
.4 degrees camber on the drivers side and .3 degrees on the p***enger side are a bit off from my starting point of the drivers side having 1/4 degree more camber than the p***enger side to compensate for the crown in the road and help the rig track right. Different area with different amount of road crown call for "local settings" though. Caster has two effects, Less caster lets the rig steer a bit easier at slow speeds, more caster helps the rig track a bit better at high speeds up to a point. Factory MII setting was right at 1 degree positive caster as were/are most mid 50's though mid 70's coil spring independent front end American cars. Those slots that the control arm bolts slide in only give you so much adjustment though.

The earlier Saginaw pumps require a different pressure valve in the pump to cut pressure and relieve the twitchy steering with the MII rack. I'm not familiar with that pump.

Check your pms as I have a suggestion for you.

 

Also was wondering since I don’t have the bed on there’s going to be a decent amount of weight change to the rear once I set it on..will that help at all with the steering?

 

Appreciate the info I’ll check it out!

 

Get a pump of a early dodge wrangler. Also a t bird rack is better than a m;s 2

 

Looks like the speedway kit comes with the t-bird rack so that’s what I got

 

I wish I hadn't seen those wheels.

 

Speedway column I'm guessing is Chinese junk, same with their U joints. Get a good column and some Borgson joints and be safe.

 

When you post a pic, hit the tab beside it that says full size

I dig that color.

 

How does someone make a steering column with play in it ?
Probably by not giving a ****.
Sloppy Speedway Column, Sloppy Speedway U-joint, Speedway Rack.....
"....a little sketchy at higher speeds" Hmmmmmmmm.

 

If you are using a GM pump, here is some info that may help:

 

First, make sure sure don't have any play in the steering. If you do, fix it.

Then, two things. First, make sure the tie rods are approximately level with the rack. If they aren't, you're going to get bump and roll steer. Second, at least 2 degrees positive caster in the left and 2.5 degrees in the right. This helps compensate for the crown in the road. After that, if it's still a little twitchy or wandering, add a little toe in.

 

It's a know issue with a GM pump and the Ford rack to have real sensitive steering. If you look at Speedway's website, they have a valve that's around $27 that fixes that. If you are referring to sensitive input, that would be my suggestion.