Chrysler's 426 Race Hemi had great success in 1964.
When 1965 came around, Chrysler decided to step
up that success to the next notch. They developed
an even more lightweight Hemi, designated the
A990 program. Chrysler built 360 A990 Super Stock
sedans (160 Plymouths and 200 Dodges).
Special features of the A990 426 Hemi:
- Aluminum cylinder heads
- Magnesium-cast cross-ram intake manifold
- 12.5:1 forged .775" dome pistons
- (2) Holley R3116 4-bbl carbs
- 312-deg duration, .540" lift camshaft
- Aluminum oil-pump body and cover
- Aluminum water-pump housing
- Aluminum water-outlet elbow
- Aluminum alternator bracket
After dyno testing a few changes were made:
- Copper head gaskets (instead of steel)
- Thicker head bolt washers
- Longer head bolts (due to the washers)
- Increased length of chrome plating on valve stems
What does all of this mean?
- Approx 600 horsepower from the factory