Are you using the stock kick down linage? If so what about the the brackets for the throttle cable etc... Usually ant time you change carb and intake it will throw off the kick down linkage. Might want to look into getting a kit from lokar.

https://www.lokar.com/products.html

 

Thanks. Here are a few pictures of the linkage. As far as I know everything is from the original Thermo-Quad and worked great for at least six months. The spring is not really tight and overall there is significant play from left to right... might those also be factors?

 

everything looks fine there. you probably need to slider under it and adjust things or make sure it is adjusted properly. the farther back the lever on the trans goes the longer it will hold the previous gear before shifting to the next and how much throttle is needed to make it kick down into a lower gear.

 

Also might want to look at the spacing from the original TQ throttle blade shaft and where the post is for the linkage. The sweep/distance may be different.

 

Here's underneath... what exactly is adjustable? Thanks.

 

loosen bolt, slide lever back some on that rod and see how it shifts/kicks down.

 

Thanks, crazzywolfie. Do you mean the bolt that is somewhat facing the camera, screwed into that cube? Thanks.

 

yes! After you adjust it make sure you have full throttle range. Back in the day any time a carb/intake was put on you had to mod the kick down linkage to get it to work properly. It may "look" ok but the sweep(movement of the bolt that goes on throttle) may be different than the stock carb. May not move enough or to much depend on the set up.