3F exhaust manifold

[Godwin]

I have a question about 3F exhaust manifolds and this may be the best forum for posting. Are all 3F exhaust manifolds identical no matter what Cruiser model, such as 60, 70, or 80 series? The manifold in the photos is a 3F, correct? Is this stud pattern, two studs toward the block and one distance from the block consistent for all 3F manifolds, regardless of the Cruiser model? I need this information for sourcing an exhaust pipe.

 

[Combat Wombat]

Ive looked on the parts site, and they list the same part number for FJ60 and also FJ70

Part No.	MANIFOLD ASSY
17100-61100		1	$1,284.83

 

[Combat Wombat]

Restored Exhaust Union Flange for 1979-1980 Toyota Land Cruisers - BTB Products - Land Cruiser Restoration and Parts - https://btbprod.com/product/fj40-fj45-exhaust-down-pipe-union-flange-oem-restored-17441-61030-1975-1976-1977-1978-1979-1980/

This looks like a simple solution too. I am nor sure on the physics for exhaust sizing for 3F engines, but I would assume if you went too big there would be a loss of torque in the low end revs.
2" seems adequate for most applications