I have a late 67 farmall 706 with the 291 gas engine. I have a few maintenance items that I am wanting to do on it. I have read some of The Tractor Vet"s postings about the heat riser in the manifold. Mine was not working and I was able to get the manifold split without breaking any bolts. I need to order some new parts for the heat riser butterfly. Can anyone tell me how the shaft, buttefly and weight are indexed when they go back together? Do the butterfly and weight face the same way? Are they 90 degrees off? Should the weight be vertical or horizontal when the butterfly is closed? Also, does the slot in the end of the shaft (where the spring slides in) need to be indexed in a certain way to make it work properly? Thanks for any information.