Trailing arms Adj or not?

[J68Bird]

I am installing a Corvette IRS into my 68 Firebird. I'm using the earlier C3 type mainly because it was given to me and it's about 2" shorter than the original. My plan is to fabricate new trailing arms, (see pic attached) and a batwing setup like the newer models. The original trailing arms are not adjustable and the cars I've seen with C4 type rears are also non adjustable. I'm looking for tips on setting up the rear location as accurately as possible. I have the car setup and leveled on a frame table. I set the car centerline up using a laser level and I've got new 2x3 frame rails in position.
I'm thinking that I can bolt on a rim, lay a straight edge across it and using the laser, shoot a beam maybe 20' out. Measure both sides against the center line and line it up that way.
Anyone have tips on making sure I don't screw this up?



J. Clear

[astroracer]

If you make the link adjustable, either in the link itself as I have roughly indicated, or with a slotted mounting location, you would have a little bit of adjustment after you get it all together. That would be a good thing...
Mark