Worked on the '69 Coronet convertible all weekend. The prior week, installed new 3.54:1 gears in the Dana 60, and waited for a diff cap stud kit and plain steel rear cover (not shipped, discontinued item), so I bought a cheap chrome cover. So, I got the studs installed, cover, filled with gear oil (one item done.)
Next, Removed the super turbo mufflers and installed huge (I think 29" long) Walker Quiet Flow mufflers. To get the mufflers to sit back to where the floor kicks up, and to make removing the exhaust easier, I cut the muffler outlet to about 1" from the case and welded a collector flange to the muffler outlet. Then cut the TTI tail pipe right at the bend, and welded another collector flange on there. Then I welded all the connections in the TTI "X" crossover exhaust system. (second item checked off.) Installed the driveshaft and fuel tank back in the car. Then I started laying out the fuel system, trying to figure where to put the external EFI fuel pump, 100 micron pre-filter and 10 micron post pump filter.