This side-by-side comparison shows the radical differences between the modified, original '69 Boss 302 intake manifold (right) and Wilson's new induction piece. Check out the runner shapes and lengths.
For now, we're going to use the same ACCEL 48-lb/hr fuel injectors. However, we'll move to larger injectors if the dyno test proves it's necessary. One interesting note about the new EFI intake and its fuel rails is that the injectors are installed straight up as opposed to on an angle, which is how squirters were positioned in the modified Boss intake.
We can't wait to have all four throttle-body holes wide open like this on the dyno-and especially on the track.
The pushrod guide plates from the Boss 340 Version 1.0 are reused on the AFD heads. We're also reusing Probe's aluminum, 1.73-ratio roller rocker arms.
Based on the huge difference in the intake- and exhaust-lift values for Boss 340's (Version 1.0) hydraulic-roller camshaft and the new solid-roller cam, longer pushrods are required. To determine the lengths we need, Probe's engine builder marks the tip of an intake and exhaust valve; then installs an adjustable pushrod and a rocker arm on the intake and exhaust sides. He notes how the rollers pass across the wet ink when the cam, tester pushrods, and rocker arms are taken through a complete valve cycle. The location of this mark shows us that an even sweep has been established on the intake valve, and the length of our new pushrod must be the same length as the test piece.
The adjustable pushrod is measured in a digital caliper. With the new camshaft and lifters, our engine now requires 7.700-inch pushrods on the intake side and 7.800-inch pushrods for the exhaust valves.
Here's our Boss 340 with its new top half mocked up. Once the necessary mods are made to the heads and intake manifold (vacuum port added), the crew at Probe will fully reassemble our project engine; then we'll be off to the dyno at Westech Performance Group to see how much performance our Boss has gained with the upgrades.