914/6 Intake Manifold Question Options

[Peeterabytes]

I am in the process of getting my 914/6 back on the road after sitting in my garage for 24 years. Finished the fuel tank, suspension, and brakes rebuild so on to replacing the Webers with some 40mm PMOs. The car has a 911 3.0 SC engine.

The current intake manifolds are 901.108.321 which I believe my father got from a 911s back in the day. Believe those are 32mm ports.

I am thinking about replacing them with new PMO intake manifolds but on the PMB website, it suggests 36mm X 40mm or 37mm X 40mm for 3.0 engine. I am thinking the 36mm. Only because I believe that is the intake port size for SC engines. And I’m just looking to make it a fun casual driver, not any crazy performance or worrying about where my peak HP comes in.

Asking you experts for advice? Stick with the 32s? Get the 36s? Or?

[Luke M]

My brother has a 3.0 6 in his 914-6 conv. He's running Weber 40ida's with PMO manifolds. He also has the head to manifold heat insulators installed. We ran into a height issue w the tall manifolds and swapped out for a shorter set. The pmo filter covers where hitting the backside of the truck wall and lid springs. Once swapped out it was ok. This issue could be from installing the front firewall mount a little high as well but not too sure. As far as which size port to run we went with the same size as the head intake port. His 3.0 has the early large port heads so matched to those. 78-79 are large port and 80 -83 are small port. I feel the 40's are a good match for his engine combo which has been modified.