66-67 Dodge Charger Source Guide

Heads Q & A


George Hupp: I’ve never built an engine using milled heads before. When I tried to install my new Edelbrock Performer RPM intake manifold I could not get the bolt holes to line up. My heads have been milled .040” (I was told!), how much will need to be cut from the intake? Any estimate on the cost?


Greg Rose: For every .010" removed from the heads, the intake should be milled .0123". If you're only removing .010 or .020 then the bolts will likely still line up. But at .040, there will be a noticable mismatch. .040" / .010" = 4, so 4 x .0123" = .049" from each bank of the intake.


Terry Hoover: Can someone put together a paragraph or two (or more) about open vs closed chamber, Different styles and their number, what it all means for design, assembly, performance, interchange, etc.


Greg Rose:

Big Block Chrysler Heads

Part Number

Engine Size

Model Year

2406516 361-383 1964-67
2780915 440 HP
2843906 383-440 1968-70
3462346 383-400-440 1971-72, 73
3769902 400-440 1974
3769975 400-440 1975
4006452 400-440 1976-78
3614476 Stage IV
4286526V Stage V

915 are the closed chamber version of the 906 head.  These heads port well and are said to have the highest flow potential.  906 heads had about a 83cc combustion chamber with 915s about 74cc stock. 

Starting with the 346 heads in the early 70s, the seats were partially hardened (but only 452s had true induction hardened seats - earlier heads need inserts for unleaded fuels).  452 heads flow almost as well as 906/915s, have the advantage of hardened seats, but have a combustion chamber of about 90cc stock.  They likely need to be milled to get the compression of 906/915s (or domed pistons). 

1967 and up heads have 2.08" intake and 1.74" exhaust.
Got most of this from Chuck Senatore at Muscle Motors in Lansing, MI.