Doug Thorley Header Pipes

Hey all ... I'm gonna install new Doug Thorleys and a Gibson Exhaust to my 04 V8 4Runner. I wanna replace the stock manifold bolts and wondering if going back to stock length will be sufficient. Do I need longer, different, better bolts? Anyone changed these out? Any advise would be appreciated!

 

I wanna say @MI-FL off roader has put some Doug Thorleys on. Hopefully he can chime in.

 

New OEM studs will be fine for fitment. Thorleys have a flange that's same thickness. I went with Titanium studs and nuts which I've had no problems with, but now I read they may not be compatible w aluminum. So who knows for sure.
You most likely know already,
Lots of deep creep or whatever brand you prefer several days before.
Several different length extensions and a couple swivels. I used mostly 3/8 drive and hand wrenches. Different peices of 2x4 for engine lifting w the floor jack. PIA but not the worst job I ever did.