I used to have a Mercury Monarch (same as Ford Granada) with the 250 ci (4.2L) six cylinder engine and 4 on the floor trans. (3 + OD). I always wanted to cut the manifold off at the head and construct a tubing set-up to use 3 side draft Harley Davidson carbs similar to what my Austin Healey 3000 used (it had 2 SU side drafts). The 3 Harley carbs calculated to have the right flow for the 4.2L six. Just a dream in my case as I didn't have the fabrication skills.
God Bless
Whisler
Frankenstein: 1989 F250 4X4, C-6, Hurst Pro-Matic 2 shifter, carbed '84 351W, Edelbrock manifold, Edlbrock AVS, DS2 ignition, 3G alternator, JBA shorty headers, no cats, dual exhaust with H pipe.