289 HI PO?

The only difference between the K Code block and the other 289 blocks were the extra deep big end bearing caps, and the unique extra bob weight behind the harmonic balancer. The actual block itself was identical. There were no 4 bolt main bearings, no extra webbing, no extra oil galleries, no differences to the crankshaft. The Mexican 302 blocks circa 1973 used the same big end caps too by the way. You can retrospectively fit those big end caps to a 1966 289 and achieve the same bottom end - although it has to be said that big end failures in 289/302 engines seem to be pretty rare actually.

There were some differences to the valve seats on the matching heads, but the valve diamater openings stayed the same as the normal heads. No extra porting or chamber cc differences. Certainly nothing like the difference between a Cleveland head and a Windsor head. And yes, the pushrod lifters were solid units instead of hydraulic units. Obviously a different cam and a better 4 venturi Rochester carb were used on the K-Code engine but I'm pretty darn sure that was it. Oh yeah, and the exhaust manifold too.

Rochester carb ? On a 289 Hi-po? Give me some of what you've been smokin A rochester Q-Jet won't bolt onto a 289 4bbl intake. As for the block, the current 302 sportsman block pretty well duplicates the Hi-po block now. Same main caps.