Proformance Unlimited's Pontiac 400...Live engine run
Pontiac 400 built by Proformance Unlimited Live Run http://www.proformanceunlimited.com/
You can view this engine package at the following link: http://www.proformanceunlimited.com/specs/pontiac_400_375tk.html
Pontiac 400 with 450 HP engine package with Edelbrock aluminum heads can be custom designed to your specific needs. All engines can be custom painted to match your vehicle at your request. We can outfit your engine with the exclusive March Performance serpentine belt system. We can also assist you in choosing the proper transmission and stall speed converter combination for your vehicle and have it shipped directly to you as your performance crate engine is being built.
PONTIAC - "The Super Duty Story" Part 1 of 3
Pontiac had an SD engine program in the late 50s early 60s, and later/briefly again in 1973/74 with the SD455. This video is regarding the FIRST Super Duty program.---In only a few years time during the late 50s early 60s, Pontiac MORE THAN DOUBLED their V8's horsepower output (described in this video), while using/keeping the same V8 engine block they used thru 1955-81. Even though the same block was kept, from 1955-62 the cubic inch displacement grew much larger than the initial 287 cuber it started as in 1955. It grew to a 317 347 370 389 and finally a 421 cuber in 1962. It eventually maxed out at 455 cubes in 1970. By 1970 ALL the other GM divisions were producing engines at 454 or 455 cubes (500 for Cadillac). PONTIAC WAS THE ONLY DIVISION still using the same block they used in the 1950s on engines that had a much smaller displacement -- 287 cubes. The 1955 287 displacement would remain the smallest displacement ever used in the Pontiac V8 block all the way until 1980/81 when a 265V8 was produced. Since less durability was required for the smaller displacement, the block was decked/butchered/lightened on the 265/301v8s of 1980/81. Prior to 1980 the block had never been decked/butchered/lightened. The 1980/81 265/301v8 blocks were about 200 pounds lighter than the 1955-79 blocks, and only 25 pounds heavier than a Buick 231V6.
Sehr Performance / Randi's 400 Pontiac
Randi came to us with a 400 Pontiac project for his 1968 Firebird. He didn't want to go crazy on the build but he wanted something that would give him performance that is better than original.
With that goal in mind Scott did some custom porting on his heads, upgraded his valve train and went with a Custom COMP cam and lifters and aluminum roller rockers. We maintained his complete original rotating assembly but had to re-balance his crankshaft, it had been poorly balanced sometime in the past and was out by 127 grams on one end and 181 grams on the other. A single plane intake with a 780 Quick Fuel carb got it breathing and the fire is lit with a Flamethrower ignition package. Custom cut and fitted 8mm plug wires are standard equipment here at Sehr. Headman custom coated headers will be added at installation time.
The results were a satisfying 543.5 Hp @ 5500rpm and torque reading of 519.8 @ 5400rpm. Corrected to sea level the numbers are 577 Hp and 551 Tq with nearly 400 lb of torque at 3500rpm.
Pontiac 400 engine after rebuild
This is engine for my new 1977 Trans Am "Racer". Specs: '73 block with stock type crank (.010), pistons (.030) and rods,'69 heads No. 46 with no mods, stock '69 intake manifold, Summit headers, CompCam 268 HE complete camshaft with stronger valve springs and 1.6 roller rockers.