exhaust studs manifold and manifold to header pipe

I have a 1990 NA volvo 240. I'm about to replace the header pipe and exhaust manifold gasket and I want to go ahead and order new studs for the manifold(the 8 that go into the head and the 3 that go into the manifold to hold the header. I read a thread on here saying the header bolts are m10x1.25 is that right? if so how long are they? The 8 are m8 x 1.25 x 45mm I'm pretty sure. I want to order stainless with hex head/allen ends.

https://www.fcpeuro.com/Volvo-parts/240/Exhaust-Hardware/?year=1990&m=20&e=914

If you click on the FCP Euro part links you can find the bolt sizes.

If you use stainless steel hardware, use plenty of copper grade anti-seize. Stainless on stainless will gaul up and seize the first time you try to take them apart. Probably why Volvo used steel and copper nuts.

Well I went there(thats where I found the head stud sizes) but all I got was the Bosal part number for the other three and just found the specs on another site. That said I am going to use copper coated exhaust nuts on the stainless studs. https://www.belmetric.com/hex-with-flange-c-3_51_53/?zenid=5g3q5ues6p3d9g9ka3nm54rt20

Header pipe to manifold studs. Thanks for the help.

m10x1.5-50mm

https://autoplicity.com/8234867-bosal-258-953-bosal-exhaust-loose-parts-stud-m10x15-40mm-o

Volvo lists the bolt dimensions on much of the hardware in the parts catalog on gcp.se.

If you are removing studs with the head/engine in the car, you are going against the odds of snapping one off. Just one stud snaps and the head comes off and goes to the machine shop.

-Lazarus

I know I used ARP 400-8013 and I ordered 2 sets for 1 head, and liked it. I found them appropriate in length on both sides (for a stock N/A exhaust head pipe and LH2.4 intake.)
The exhaust side works like a dream, the intake side is a tiny bit more hassle removing the 12-pt nuts without a swivel. If you wanted to spend less, I'd say using them on the exhaust side only would be a good move.
For the down pipe, I used about $60 and the McMaster-Carr catalog to assemble stainless studs/bolts coming down from the manifold and sets of stainless steel spherical washers to deal with the non-flat surfaces the nuts bear upon. The results are no leaks, no bending fasteners during tightening, and the ability to remove and reuse all of the above when removing the head for whatever things I've later removed the head to do.