Lean Burn Thermoquad?

[streetmachine]

Hello again, I'm trying to remember something from a while ago in regards to these carburetors. But, I'm trying to remember if a Lean Burn carburetor can be jetted properly to run properly once you run an electronic ignition? One thing I've come across with the later carburetors as well is the lack of idle speed adjustment as well on the later car applications.

I'm just curious because I have a 79 TQ from a LB car application and I have freshly rebuilt TQ with an 80 truck application. The '80 truck carburetor is less complex and allows me to adjust the idle speed and I think a vacuum port to allow the advance from the distributor as well.

I've read a couple of times a LB carburetor even if jetted properly still may not function correctly or be good enough plus they don't have the port for the vacuum advance. I've read a truck application or earlier TQ would be the ticket to use a LB car converted to the electronic setup? Just curious. Thank you in advance.

 

[idrivemopar]

Personally, If you have a 79 or newer I would ditch it. I believe there are some more significant modifications that have to be made, expecially with vacuum ports and idle adjustments as well as the oxygen sensor solonoid, the lean burn thermoquad for an older year version setup can be modified easily or just locate a non lean burn version or just use a modern carb.

 

[Northern Runner]

x2 on that!

 

[WileERobby]

We used to do these often, back then. Easy way is just get a pre LB TQ, which is what we did all the time.

 

[rumblefish360]

Oh it has been a all so very long time since I had a Lean Burn TQ to mess with.

The two screws up front can be hacked into for use and the vacuum port is not tapped but can be tapped for use. The idle speed screw on the severe side should be there, it has been a while though, I just can not see it NOT there.

Down the primary barrels on the front side of the venturi are two small holes that bleed air into the carb. JB Weld them closed.

Use AFB/Edelbrock rods bent to size (3/4 inch shorter) to use in the TQ and clip them to fit the tree.

That should make that TQ comparable for use to the older ones. If you opt. for a older TQ, anyone of them will work well. Just stay away from the first year and the race models since there air bleed designs. The electric choke models have the small primary. But are super handy for a aftermarket intake that lack a choke well.

 

[streetmachine]

Well, I got ahold of an '80 truck TQ off a 360 that I will use for now. The only thing it has is the electronic vent solenoid. Other than that I'll give it try and see what happens. Hopefully, someday fuel injection soon enough.

 

[rumblefish360]

Fi-Tech? Lots-O-bang for the buck.