If you have follow my fuel problems, you may have seen that my economy has suddenly improved. This is mainly due to removing my in-line disposal fuel filter and by replacing most of the rubber fuel line with a hardline. However, before I tried this simple and effective fix, I went after the big stuff in the engine...

To rule out the possibility of burnt valves, I temporarily swapped on the head from my 500,000 B18D last week. I found the performance and economy unchanged and the valve unburnt.

I had the car's original cylinder head - rebuilt and put in storage about 20 years ago by the original owner. The car's original head had at least new intake valves put in, so today, I decided to install the cleaned up cylinder head that was original to the car.

In the course of removing the head and the associated bits, I considered installing a split manifold setup and quickly realized that I had better do so, because the vacuum fittings on my combo manifold were cracked. The cracks do not go deep into the manfold, but I'd bet that it was causing some sort of manifold leak. Can such cracks be fixed? I'd hate to toss a perfectly good (otherwise) 1967 double-downpipe manifold. I'm thinking that I must have over-torqued the NPT threads which lead to stress cracks over time.

Anyway, I put the new head on with new gaskets and the new manifolds. I made up a set of 1/4" half-washers and installed my NOS aluminum intake, and a cleaned up iron double-downpipe exhaust manifold that JohnMC gave me with that old 1800E

The intake has two fittings and this is where my question lies.

I have a 140-style brake booster setup. Should the vacuum to the booster be attached to the center-bar intake port, or to the forward vacuum port - located
on the end of the balance tube by the front Carb?

Does it make a difference? The PCV hose is better situated to go to the center port...

Are there any linkage modification that are needed? I test-fit my linkage and noticed that the geometry is a bit different now. The center vacuum port will get in the way of my old linkage setup. Is that normal?

I do know the downside of a split manifold (stays colder longer), but with spring arriving I'm not as worried about that right now.