455 Pontiac engine being run on engine dyno with Edelbrock performer heads.
1976 6x Pontiac 350 400 455 Heads Trans Am Firebird. 625.00. View Details. ... Cometic Gaskets 4.200 Mls Head Gasket .040 - Pontiac 400-455 Pn - C5769-040. 91.15 ...
True, the 400 cubic incher made a little bit more power than the bigger engine (4 to 10 hp, depending on who you believe), the 455 had it where it really counted - 500lbs. ft. of torque.
If you have 6X-8's now and put 6X-4's on your 400, you'd have a W72 engine, with about 8.1 compression ratio, up from 7.6. If you stroke it to a 455 later, you could use either heads. The -4's would make about 9.5 compression on the 455. The -8's would be closer to 9.0 in a 455. Probably have to use Premium with the -4's in a 455.
389 Cylinder Heads and Valvetrain. Correct cylinder heads for the 1965 389 GTO are cast #77 and have 1.96" intake/1.66" exhaust valves. For 1966, most GTO models had a cast #093 head. California-bound GTO's in 1966 had different cylinder heads with an internal air galley. In 1967, the 389 Pontiac engine was enlarged to 400 cubic-inches.
Buy ARP 1903601 High Performance Hex Head Bolt for 400 Ram Air II/IV and 455 HO, Ram Air II, Super Duty with Round Port Heads Pontiac 68-74: Head Bolt Sets - Amazon.com FREE DELIVERY possible on eligible purchases
1932 Flat-head V-8. The first V-8 engine that Pontiac offered was in 1932. It was the same 251-cid 85-hp flat-head V-8 used in Pontiac’s almost-dead parent make, Oakland, during 1930 and 1931. In 1933 and 1934, Pontiac built only eight-cylinder cars, but they used a straight-eight rather than a V-8.
The 6X head was installed on the 350, 400 and 455 Engines during the mid to late 70's. The Boss Stamping to determine the cc's of the 6X heads are as follows: A # 4 is 91 cc's (Installed on both...
Jun 10, 2014 · He has 6x-4 heads (I'm pretty sure that was stock) so 2.110 I.V. and 1.66 E.V. I know nothing about building Pontiac motors, looking for advice on what Pontiac 350's like. Split duration/Single pattern, rough duration needs, lift, exc. Comp Cams XE256H 212-218 256-268 .447-.455 or Comp Cams XE262H 218-224 262-270 .462-.470 look appropriate.