Just thought I would add this how to - it can be difficult to get the throttles properly synchronized running from one bank to the other.

This makes adjusting throttle body opening easy.

First step is to adjust ONE throttle for 0.002" clearance at the top between the butterfly and housing with the throttle closed. Then remove any backlash in the rod. I did the left first.

The first pic shows inserting 2x 2mm bits of steel to hold the throttle slightly open.

Next pic is the LH throttle body stop measured with feeler gauges with the 4mm shim in the pedestal. Once this was done I moved to the RH side and set the opening the same with feeler gauges.

Now both throttles open within a poofteenth of each other.

 

so if you have the throttle shimmed at 4mm, are you setting the throttle bodies at 4mm?

 

No - the shim in the throttle is only to open the throttles so a measurement can be made. Each throttle is then adjusted so they are the same distance from the stop.

I'll edit the post it is a bit confusing.

 

ahh...got it...okay that makes sense now.

 

I've bought a pair of those black throttle bushings that are supposedly often cracked, missing, etc. on our 5.3s, but could not figure out where they go. Looking at your pics, in #3, is that the bushing toward the bottom?

 

Bloody well done.

That "poofteenth" is going to drive Google nuts. AAH the Aussie lingo, so special.

 

Start at the capstan, follow one of the rods to the end of the manifold, here you will see the lever the throttle rod is pushing is fixed to the throttle butterfly actuating rod running forwards to the throttle body.
You will see that the cabin end of this butterfly actuating rod is set in a hole in a triangular bracket. It is into this hole that the black throttle rod bushing fits.

 

How much free play do the throttle rods have when the throttle s closed?

 

i do that differently, i get the engine up to temperature after a rough setup, and heat gun measure down pipe temps, NO catalyics!
then adjust linkage slowly to get them even temps, make a drive and measure again, sometime a slight readjust!
works for me?
a made bushings from aluminum rod, and a lathe, any small shop could do them!

 

the bushing fits on the end of the shaft near the linkage. Yours are probably completely gone mine were. The shaft was just loose metal to metal. The bushings I bought did not fit without turning down one end so they would pop in. I put them on and easy out in my drill and spun it against a file into they fit.
hope this helps.