Finished the rear axle swap. Ended up being a bigger pain than I anticipated because I forgot that the axles had to be pulled to change the brake backing plate. Then the backing plate of the drum brakes had a smaller diameter hole than the disc brake with the 9". I tried purchasing new backing plates but the plates I bought ended up having a smaller hole than the description online stated. So I ended up getting a hole saw out and opening it up. I would have just stuck with the disc brakes except they are on a 5x5" bolt spacing and my Firebird rims wouldn't fit. Then scope creep happened, I put new leaf springs and bushings in too.
Then I started on the exhaust. Finished tack welding the turbo header pipes together and did about half of the finishing welding before the wind picked up. So I switched gears to the main exhaust. 4" from the turbo to the rear axle then 3" over the rear.
3" over axle pipe fit as advertised. I aspire to some day have fireballs popping out of this on the 2-step.
The 4" pipe fit surprisingly well. It does not even hang as low as the 2.5" system I have on the car. I did end up flattening a 12" stretch by about 3/4" to clear the floor board of the rear seat. I need to add two exhaust hangers for the long stretch of pipe. I have a piece of wood holding up the front of the exhaust system because I do not have the v-band flanges welded on yet. If you look close I installed a driveshaft loop as well.
From the other side. Cannot even see it past the 2.5" exhaust.
I am going to need to re-route a handful of wires and fluid lines to clear the exhaust pipes, but nothing too bad, mostly needs good underhood housekeeping. The exhaust cross under is definitely going to be the low point of the car, and I'm sure I'll need to re-visit it sooner rather than later.
Next up is finish welding the whole system up, checking the best I can for air leaks and addressing accordingly, run a large pipe cleaner or such through the system to knock all the crap out of the tubes.
Due to time constraints, and going to the drag strip, I'm not going to put my good short block and head in it until after Drag Week. I do not even have the short block back yet. I have another 250 in the shed I'm going to open up and take a look at the rings and bearings and it may end up being my turbo test mule. If I put that short block in, I may put new NOS valves in my current cylinder head and clean up the ports a bit more than I have to match the intake and header port sizes. I wouldn't worry too much about the exhaust port being smaller than the header, but would want to gasket match the intake port with the intake runners.
