1968 Pontiac GTO

[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


pc

[CycloneFE]

Originally Posted by Paul Ceasrine

Ray,





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

pc

That seems a touch slow, my father was turning that at Alton with his 65 Tempest. 326/285hp "HO" 4speed and a 3.36 posi. I know my father wasn't the best, but he knew his car and it is still the same one sitting in my shop. Still the same down to the original hoses. It is the car that made me a car guy.