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440roadrunner · 11-10-2007, 06:58 PM

Big block heads should pretty much interchange, but there ARE some differences. Earlier heads, like the single 4BBL 426 and the "pre Roadrunner" 383 heads didn't have decent ports.

383's don't really have 440 heads, it's just that "they are the same." Speaking here of the 335hp 68 and later heads.

If you can find the rare 66-67 440 GTX heads, and I've forgotten the casting no. (907? 903?) you've got a rare pair.

HOWEVER--some of the later heads might be even better FOR YOUR application. This is because later "smog" heads, even though might have larger combustion chambers, and might be lower compression, have better valves and seats--for no lead fuel. This can be an advantage on a street car on pump gas.

The things that will NOT fit between 413/426/440s and the 383/ 400's is the intake, distributor, (I think) rods, pushrods, and without major mods, the crank.

11-10-2007, 06:58 PM	#7 (permalink)
440roadrunner Senior Member Join Date: Nov 2007 Posts: 272	Big block heads should pretty much interchange, but there ARE some differences. Earlier heads, like the single 4BBL 426 and the "pre Roadrunner" 383 heads didn't have decent ports. 383's don't really have 440 heads, it's just that "they are the same." Speaking here of the 335hp 68 and later heads. If you can find the rare 66-67 440 GTX heads, and I've forgotten the casting no. (907? 903?) you've got a rare pair. HOWEVER--some of the later heads might be even better FOR YOUR application. This is because later "smog" heads, even though might have larger combustion chambers, and might be lower compression, have better valves and seats--for no lead fuel. This can be an advantage on a street car on pump gas. The things that will NOT fit between 413/426/440s and the 383/ 400's is the intake, distributor, (I think) rods, pushrods, and without major mods, the crank.