difference between 440hp and 440 hp2

[boss351]

hi ,what is the difference between a 440 hp and 440 hp2 ,i know the block it's the same ,is it internal parts or what ,thanks !

[michel426]

i beleive that most of the HP2 440 had the six-pack crank and rods.

[boss351]

no ,i have a superbird in my garage ,the block is punch hp on the pad and the short block is a six pack and the block is number match with the car ,i read on 440 source ,the block are the same ,440 hp and 440 hp2 , but Inside ?

[John Dinkel]

In the old days there were two 440's. One was 350HP and was lower compression.and different cam. The 375HP had higher compression and different cam and valve springs and pistons. Don't know how NHRA differentiates the two combos. They both had 4 Barrell carbs.

[ss3011]

My 1967 GTX came with a 440HP, rated at 375 hp . It was different from the 440 , 350hp because it had a larger exhaust valve, even though the head casting was the same, HiPo exhaust manifolds, a bigger cam, and it had a bigger AFB.

[Larry Hill]

The only difference I see in a 440 block compared to a HP block, is the HP engine had larger wire diameter valve springs with a damper. The standard 440 had a single spring with out a damper. 1968 440 and up all had the same size valves 2.08/ 1.74.

[GTX JOHN]

Boy am I showing my age!


ANY Block stamped HP has the large camshaft and better valve springs....
NO other difference in block....HP had windage tray ( as well as
some Industrial engines ).

Difference between HP and HP2 was ONLY the Shift when engine
was assembled:
HP = Day Shift
HP2=Swing Shift


There are many rumors over the years....but I believe that is the true story!

[boss351]

ok,thanks for all response !