Pontiacthunder - 12 Second 400CID Pontiac Build

Pontiacthunder has collected data and tested many Pontiac engine combos and has come up with, what we feel, a nice collection of builds to make your Pontiac perform to your needs.
Over the next several months we will list detailed builds with performance levels from 12 second ET's from a relatively stock 400, to deep into the 9's with a 455. We’ll even take you through the build of a 517CID Pontiac Monster destined for sub 8 second quarter mile times from one of Pontiacthunders very own members.

This month, check out a simple build for a 400CID Pontiac that is geared for the budget minded! This combo has run in the mid 12’s at 110MPH in one of our own cars and is reliable enough to be street driven on pump gas!

Engine:
400 bored 0.030 over

Cubic Inches Before/After:
400 / 406

Carburetor:
Q-jet, jets 0.070 pri., CP sec. metering rods

Intake Manifold:
Performer RPM

Fuel System:
Stock GM with 3/8-in line

Heads:
6X, 2.11/1.66 valves, three-angle valve job

Flow Numbers:
Gasket-matched only

Pistons/Rings:
Speed-Pro forged / Speed-Pro

Rods:
Stock 6.625 in, ARP bolts

Compression Ratio:
9:1

Crankshaft:
Stock cast

Rotating Assembly Balanced:
Yes

Camshaft:
Crower hyd. 239/241-deg dur. at 0.050, 0.500 / 0.500 with 1.50 rockers, 112 deg LSA

Installed Position:
2 deg adv.

Rocker Arms:
Harland Sharp 1.50:1 roller

Ignition:
Delco points, stock coil, stock replacement wires, AC R45TS plugs

Total Timing:
36 deg all in by 2,800 rpm

Exhaust:
Ram Air manifolds, 2.5-in Dr. Gas X-pipe, 2.5-in pipes, 2.5-in DynoMax mufflers

Power Adder:
None

Transmission:
Turbo 400 with shift kit

Converter:
Stall speed approx. 2,500 rpm

Shifter:
Stock

Rear:
12-bolt posi, 3.55:1 gears

Estimated E.T @ MPH:
This combo should be good for mid 12's in the 110MPH range at 3700Lbs. Remember, tuning skill and track conditions will play a huge roll in the final outcome of your build.


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