Whats different between a 360 horse 454 and a 390 hp 427? I have a 427 CE engine and was wondering whats different here?
Also what would the compression be using the original 69 pistons with oval port open chamber "049" heads?
Thanks.
Ron

I gotta book around somewhere that tells the spec's of the different coded/years engines but just for a guess, I would say cubic inches and gross vs net hp ratings???

Again please, how far am I off guy's??? pdq67

PS., they only ran two heads, (oval's and rect's), and about three cams in the old engines.

The .398"/.398" or .430" thereabouts, (exhaust vary's some), the .461"/.480" and the .520"/.520" solid!

And the 396/402, 427 and 454 were all kinda spec'ed the same but went up in size.

And I am not getting into the big 427-, L-88 and stillborn 454, LS-7, but they were build almost identical except for blocks...

pdq67

What I'm getting at is, the engine originally had closed chamber heads and 10.5 compression, now it has open chamber heads. Just wondering how much that dropped the compression.
Ron

Oh,

OK, about a point if not tooo far off.

Maybe a schosh more?? pdq67

I bet you are closer ton 8.5:1 with those open chamber heads and closed chamber pistons.