Guldstrand with tubular uppers

[67rstbkt]

First, I apologize for posting something that's been discussed over and over. After reading through all the information I could find, I'm still undecided if I should do the Guldstrand mod on my Firebird.

I have Global West tubular upper arms that will be going on the car and I'm just about to begin working on my subframe. I know that I can do the Guldstrand mod with the new arms, but should I? Can someone please shed some light on this for me, in layman's terms? I know the basics, but need some schooling on the specifics.

Thanks :twothumbs

[sik68]

I have the Global West upper arms as well on my 68 Camaro and no Guldstrand mod, and with "Built in 6 degree's of positive caster," my 26 inch tire nearly rubs against the rearward part of the fender at full turn...I had to remove the hex head bolt as it would chew up my tire. Granted, my alignment is not spot on yet, but I don't know how much more caster it could take.

[CarlC]

All aftermarket arms do not address the positive camber gain of the stock geometry. That requires either a taller spindle or moving the upper A-arm pivot point (G-mod).

Aftermarket A-arms that add caster combined with the G-mod's additional caster mean that you may have a lot of caster. It can be adjusted out with shims.

It may be better for you to just perform the vertical adjustment of the G-mod and not the fore-aft/caster part.

[68Formula]

Read this article from PHR:

http://www.popularhotrodding.com/tech/0607phr_car_handling_tech/index.html

It also includes the latest version of the Gulstrand Template which you can then print to the correct scale.

Unless you're planning on going with a spindle that improves the negative camber gain, I'd do it.

I'm wondering if the subframe on the other poster's car is set too far back. I have a 25.7" tire with Gmod and DSE arms that total 4°, but it doesn't even come close to the fender bolts. I've also heard a few people say they had to "clearance" the firewall for HEI, and for me (and others) that was not an issue either. I'm sure there is a bit of potential variance on these cars either from the factory, or when reassembling for restorations, or repairs. So you could probably adjust it within some allowance without causing other issues. Just make sure it's still square to the body.

[6'9"Witha69]

I believe the DSE and Speedtech arms push the LBJ forward to avoid this issue. The LCAs work in concert with the UCAs to keep the wheel centered in the opening.

[67rstbkt]

Thanks for all the great info so far. That PHR article was pretty good. So far, it seems to me that I won't be hurting anything by doing the G-mod with my Global West Arms.
There was a car on one of the Pro-touring forums and one of the magazines several months back (a blue first gen Camaro) that used Global west uppers, stock lowers to save on cash (with Del-a-lum bushings) and the G-mod. I was kind of trying to model my setup after this guy - I have a tight budget and I'm trying to put the cash where it matters most.

[pollusky]

Hi guys i was reading your topic since im doing some research about the g mod , what were your results 67rstbkt do you really feel a diference and how much the tire move back from original? Thanks

[alphaenvirmgt]

I have a wild idea...why not call the manufacturer (Global West) of your control arms and ask them?
Conrad