Our plan was to find flow by porting the heads and upping the valve diameter to 2.02/1.60 with a set of Milodon street valves.

Valve shrouding isn't any more of an issue than with other small-block Mopar heads, since as part of the valvejob the chambers were cut concentric to the valve out to near the line of a Fel-Pro gasket. This makes the chamber quite a bit wider than the 318's stock 3.91-inch bore in the area adjacent to the valve.

To address this, the bores were chamfered (notched) to minimize shrouding by the shelf left where the chamber meets the bore. Contrary to popular misconception, 2.02-inch intake valves fit the 318's bores without a problem; in fact 2.08-inch intake valves won't hit.

Click to expand...

At the other end of the passages, the seat area was prepped with a Serdi-machined cut of the chambers out toward the head gasket line to minimize chamber shrouding of the valve. The oversized seat form was cut, along with a 75-degree bottom cut, which greatly opened the port bowls. After machining, the hand-porting involved blending the machined cuts into the as-cast bowls, streamlining the valveguide bosses, then blending and widening the short turn to a smoothly rolled form from the port floor to the valveseat, eliminating the various factory humps in the corners of the turn. The fully ported No. 302 heads with larger valves installed showed an intake flow improvement of nearly 60 percent to a respectable 215 cfm at a peak of 0.500 lift.

Are these low-buck heads? Getta grinder and learn to use it, and the answer is yes.

Click to expand...

we employed four-into-one tube headers with 15/8-inch tubes, supplied by Hooker.

Click to expand...

Skipping a low-rise dual-plane, we went straight to the Edelbrock AirGap two-plane intake simply because we know they really work

Click to expand...