An assumption based on reads, but there exists a general fear of manifolds cracking/warping on early F derivatives, that probably plays into the decision to, at least, attempt the readily available 3FE.
From there, guessing an educated decision can be made......if that's even possible, considering.
Toyota improved each manifold rendition from early carb'd to the 1FZ-F, with very few reports of 3F manifold issues that the late 2F had, from the earliest 3F in the mid 80s, to the 90s when. production ceased.
It's a three piece design, but integrated together in a manner that is stated to allow expansion while lessening warpage.
That was one of the primary reasons for utilizing along with a freer flowing intake and exhaust.
What I get for reading.
The two exhaust manifolds are coupled, for lack of better.
How does a perfect fitting gasket play into all of that?
I don't know......but this is usually the point in these where it'd be easy to start "modifying" or short cutting. Not saying that any other solution is a short cut, but for lack of absolute knowledge, I resort to trying to maintain continuity.
The ultimate oxymoron.
Dumb and smart at the same time....
