I've only had 1 set of TTI's. The installation was pretty straight forward. I installed them in a 74 Duster 360, 4-Speed, Powersteering car. I did install Schumaker engine mounts.
Based on the information I found on this great typically there is an issue with the zbar making contact with the header. When I spoke to Sam at TTI about this they were aware of the issue. So he made a small block Z-bar to correct the issue. I bought one and it it works perfectly.
Good luck in your decision.