Anyone have or know where i can locate specs for a 1966 S-code 390? its found in cars and makes 335hp/427lb-ft torque.

im looking for intake/exhaust valve sizes, possible stock head flow and cam specs.

thanx!

 

Its my impression this is a gt model. The heads are fairly standard. I think the have the extra bolt holes on the exhaust but thats about it. The valve sizes should be 2.02/1.55. These heads should flow about what c8ae-h and d2te-a flow. Kurt, has a set of flow figures and the ones I use are below.

heres what i got for cam specs same as 428cj
270/290
.481/.490
46 overlap
seat
18 72
82 28

(-30) 22
28 (-24)

I am not a 100% sure the cam timing is right there.
There are many better cams today than old factory techno.

Heres what i use for head flow:
.100 63 46
.200 115 88
.300 168 120
.400 193 138
.500 202 143
.600 207 145

 

thanx!!!...

 

fordeverpower is correct (the cam specs are close enough) and the GT heads have the stagger exhaust bolt pattern. The engines also came with a 600CFM Holley with vacuum secondaries. The stock exhaust manifolds for these engines were not the standard log type and flowed a lot better.

 

Plus the GT head had a better valve spring than the regular heads.

 

I run a 67 GT engine in my 66 4x4, this is a great engine, gets good mileage and has more power than I need to get into trouble with.