Do a trial mockup of your headers, mounts, and especially DIPSTICK tube before installation. It will help you get an idea of the order you should install them to avoid as many headaches as possible. Some parts/bolts would have been impossible to install had I done them in the wrong order. I also had to do a small amount of clearance grinding on my mega-block for the exhaust and wouldn't have known about it without a test fit. My Schumacher conversion mounts + TTI headers required some K-frame clearancing per the instructions, but maybe other brand's mounts are better.

Last thing... TTI's are expensive because they're worth it.