My driveshaft is lowered because of the lift kit(dropped front diff.) So I might not have a problem with them.

 

OP, what did you decide to go with?

What tsp 1-7/8" headers fit our trucks?

 

@oakley I used the cal-speed 1 7/8s and there 3 1/2 Y pipe. The quality of the headers was great for the price, however the passenger header hit the top of the frame. Now there is a disclaimer on there site about the motor mounts being changed if they are old, (my truck a 99)I did not do this I just notched my frame
I will be swapping a 6.0 with the next month and replacing my motormounts with GM oem's, I will at that time know if it helped or not.

 

Do you have any pics of the notch you made?

I just finished installing the 1 7/8 headers and installed new motor mounts and a new trans mount but I still ended up notching my frame too. The O2 bung on the passenger collector is also too far back, I can't use the upgraded clamp that came with them, I had to use cheap crush style clamps to avoid interference with the trans crossmember. The driver side header also hits the steering shaft bolt. I will have to trim it to get the required clearance.

Over all I'm glad I got them installed, but wish I had spent the extra coin to get some headers that really fit.