im debating on using either mild steel 16g or alumized 16g. and also what would be better, 2.25" or 2.5" ? im going to use 3" for my dp.

 

Stainless...mild will not like the heat.

 

Since when? Just curious as I've seen mild steel used for hot pipes in compound setups before and it worked fine.

 

I built my xover out of 16ga 2.5'' aluminized. Be sure your flex joint is rated for turbo use.

 

flex joint = flex pipe ? how do i know if its rated for turbo use

 

it has an inner liner

mild will work, but will crack and corrode fairly soon

 

If youre building a log youll need something thick, like sch 10. I used 16ga mild for my hot pipes but I also use cast manifolds.

 

I actually plan on keeping the truck for a long time, therefore I'm going with a kb log

 

I plan to keep mine for a while too lol. I went with mild steel Bc it was cheap and I could mig it. And it's held up just fine for 8k miles and over a year of driving. The next setup, I'll build stainless tubular manifolds.

 

X2 on the mild steel. It works but won't last nearly as long. I would do mine in stainless if I had it to do over again.

I also did a 2.25 crossover. I was trying to save as much ground clearance as possible. Ended up being more of a pain then it was worth IMO. 2.25 parts aren't as common as 2.5 and kbracing logs are made to fit a 2.5 crossover iirc. I had to have kyle send me a log without a vband and I welded mine on. Just a hassle. I'd just go 2.5 because its more common.