[Paul Ceasrine]

Ray,

For 1968, Pontiac GTO w/400 engine, car weight #3504 lbs.

400/350 HP (Standard engine car),,,,,,,,,,classed in E/S (10.01 wt/hp)
400/360 HP ('HO" High Output Engine),,,classed in D/S (9.73 wt/hp)
400/360 'RA I' (Ram Air I Engine),,,,,,,,,,,,,classed in D/S (9.73 wt/hp)
400/366 'RA II' (Ram Air II Engine),,,,,,,,,,,,classed in D/S (9.57 wt/hp)

I'm no Pontiac expert, but I think this is the 68' 400/360 'HO' specifications.
The 400/360 'HO' was the first performance engine option for the 68' Pontiac.
It was also known as; the 400/360 HP 'Non-Ram Air Engine'

Block Casting #'s: WS or YZ
Pistons; 10.75-1 compression
Cylinder Heads; #16 casting's (2.11" Intake / 1.77" exhaust) (72 to 75 cc's) (Open chamber)
Cast iron exhaust headers
Camshaft; (Hyraulic) .425 intake lift / .424 exhaust lift (288*/301* duration) (119 Centerline) (63* Overlap)
Cast iron intake manifold
Rochester Quadra-Jet (750 cfm) Model #7028267

The Rochester carb on the 400/360HP 'HO' was different than the 400/350HP carb,
with a larger Main Rod, and some other minor up-grades;
Throttle openings: 1 3/8" Primary / 2 1/4" secondary
Main Jet: #72
Main Rod: #41
Spring: #7037305
Secondary Rod: #BE

The #16 Cylinder heads, had regular valves, screw-in studs, dual valve springs and 'D' port exhaust.
Considered a good general all-around performance cylinder head.

A true performance test by Motor Trend Magazine (December, 1967)
400/360HP 'HO", TH-400 Automatic Transmission, w/3.23 Posi Gears
G77 x 14" tires
15.10 @ 90 MPH

Suprisingly, 400/360HP 'HO' production numbers are quite high, only a ($76) option.
9303,,,,,,,, Manual 4-Speeds
4007,,,,,,,,,TH-400 Automatics
13,310,,,,,,Total


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