Sizes. Measure in middle of opening and lengths in middle of runner.  These are just quick measurements, do not consider them gospel.

Cylinder Head port length + Manifold port length = Total induction length

Small Block Manifolds

Holley 300-110
inner runner: 2.94 CSA, 4.625 long
outer runner: 3.36 CSA, 5.500 long

Edelbrock 2925
inner runner: 2.89 CSA, 5.580 long
outer runner: 2.85 CSA, 6.560 long

Edelbrock 2925 (NEW PLENUM DESIGN)
inner runner: 3.10 CSA, 5.500 long
outer runner: 3.00 CSA, 5.750 long

Edelbrock 2970/2971
inner runner: 3.26 CSA, 5.200 long
outer runner: 3.29 CSA, 5.620 long

Edelbrock 2892
inner runner: 3.58 CSA, 5.420 long
outer runner: 3.66 CSA, 6.300 long

Edelbrock 2978 (Victor E)
inner runner: 3.35 CSA, 4.700 long
outer runner: 3.52 CSA, 4.950 long

Hurricane (Bowtie)
inner runner: 3.34 CSA, 5.540 long
outer runner: 3.70 CSA, 6.420 long

Holley 300-25
inner runner: 3.34 CSA, 4.380 long
outer runner: 3.45 CSA, 5.070 long

RHS SBC 
inner runner: 3.20 CSA, 4.760 long
outer runner: 3.48 CSA, 5.600 long

Edelbrock 2858 (18 degree) 
inner runner: 3.65 CSA, 4.260 long
outer runner: 3.85 CSA, 4.300 long

Pro-Filer/Wilson 13º
Inner runner: 4.35in² opening, 5.250 long
​Outer runner: 4.50in² opening, 6.250 long

Pro-Filer/Wilson SBC
inner runner: 3.30/3.10 CSA, 5.500 long
outer runner: 3.60 CSA, 6.000 long

Motown 040 SBC
inner runner: 3.15 CSA, 5.100 long
outer runner: 3.45 CSA, 6.000 long
​
URE 23º HULK
inner runner: 4.27 CSA, 5.400 long
outer runner: 4.62 CSA, 4.700 long

URE 23º HULK VER. 2
inner runner: 4.42 CSA, 5.550 long
outer runner: 4.76 CSA, 5.625 long

P2E Iron Hide
inner runner: 3.29 CSA, 4.450 long
outer runner: 4.19 CSA, 5.000 long

Weiand 7532
inner runner: 2.38 CSA, 4.000 long
outer runner: 2.61 CSA, 4.525 long

Big Block Manifolds

Edelbrock 2927
inner runner: 4.50 CSA, 6.000 long
outer runner: 4.58 CSA, 6.500 long
outer runner w/lip: 4.280 CSA

Pro-Filer Sniper JR
inner runner: 4.60 CSA, 5.000 long
outer runner: 4.40 CSA, 5.700 long

C-Monster C-Style Ford
inner runner: 9.60 CSA, 9.38 long
outer runner: 8.50 CSA, 6.38 long