The closed side of the intake is pretty tight on the M112/3 engine...
Air filters built into the sides of the engine cover, (straight line feed from either side of the rad).
Both feed to a single point at the back of the cover... Which locates directly onto the MAF.
90° duct (inside corner is barely an inch long).
Throttle body which is bolted to the plenum which in turn has a variable valve built in.
It’s possible that I disturbed something whilst replacing the breather hoses, these feed to the 90° between the MAF and TB as there's a few vac lines in the same area.
Thinking about it, the idle could be a touch high, need to look at the live data to confirm, but rev counter would suggest 775-800
