fordracing65,
Well they look the best but that is subjective.
You have done a side by side comparison? That’s cool. Can you post your data? Sounds like it would be interesting to read.
Intake manifolds are compromise items. You can have one that makes good low end TQ but its high rpm power will suffer and visa versa.
I worked on a sprint car and a drag boat for several years and my experience was that Mech FI (constant flow) set-ups out-powered the carb deals. The top tubes (Bells), length, diameter and taper can be changed to make the highest tq and hp within the engines desired rpm range. I’m using the Kinsler/EFI SCJ on my big motor. If I thought I could make more power with something else, Id get it. Tuning an EFI IR system in no different from any other.
The manifold (looks like a version of the FR500 manifold) on your motor is essentially an IR manifold, fed from a common plenum and a single throttle body with secondary butterflies to help low and mid range tq. I really like the 4v mod motors. I have a 96 Cobra with a Vortech blown and aftercooled 4v 4.6 and a second motor on a stand in the shop.
The Lucas “timed” metering system was miles ahead of a constant flow systems (back before EFI was an option) from a drivability standpoint. That’s why the Can-Am guy ran them. Lucas (the “Prince of Darkness” company) built the metering parts and injectors (driven by the cam via the distributor normally) that you would fit to your manifold. From what I know, the MacKay (Brian Mackay) manifold was a copy of the early Crower manifold but specifically modified for the Lucas parts.
Jason