SS/CS question.
 

I know you have to run a steel head in C S but can it be 14 degree steel heads?

Re: SS/CS question.
 

Nope.
Only Chevy cylinder heads approved for SS/CS are the Chevy Bowtie cast iron head, and the Dart P/N's 10710040PF or 10220010.

Prior to the rule change in Comp Eliminator Jr. Fuel class which now allows aftermarket aluminum cylinder heads, the Pro Action/RHS 14 degree head was the cylinder head in use by the Chevy powered cars.

Re: SS/CS question.
 

While on the subject of the SS/CS what are the approved ford heads? N351/352?

Re: SS/CS question.
 

Yes, the approved Ford cylinder heads are the N351 and N352.
Many years ago I submitted the Pro Action/RHS Ford Cast Iron heads with the 58cc chamber, 200cc and 230cc intake port for approval, however, a decision never took place.
I believe the Dart 200cc cast iron cylinder head may be the same as the RHS head. Dart and World Products offer cast iron heads that could be submitted for approval.

Re: SS/CS question.
 

There is a cast iron LS head that was only a couple years and I think only on trucks. Wonder if that head is legal.
Never seen a LS engine in modified.

Re: SS/CS question.
 

You can find the 6.0 LQ4, P/N 12561873 cylinder heads dirt cheap.
It already has a 210cc intake port volume and 75cc exhaust port volume. They are the same cathedral cylinder head configuration as the 317 aluminum casting head. In stock form, they flow over 250 CFM on the intake and over 180 CFM on the exhaust. There are some that have been ported flowing over 330 CFM on the intake side.

Since it is an OEM cylinder head and for use in Modified class, there should not be an issue in the approval of the head. You can even find brand new virgin castings on eBay all the time.

I tried to persuade Adger Smith to build one for his car. With all the LS aftermarket parts availability, I believe it would be a very competitive performer.

Re: SS/CS question.
 

The N351 head for Ford isn't on the list of NHRA Approved Parts because it isn't "aftermarket". It has a Ford part number M-6049-N351. So it's legal but not listed on any NHRA list. Anyone interested in this head watch your pocketbook. Special headers. Offset valves mean offset lifters and rockers. 10 degree valves let you run true flat top pi$ton$...

Re: SS/CS question.
 

Only available in a truck. Rules state passenger car only.

Re: SS/CS question.
 

Dart did make a iron Ford motorsports head in 95, part # m-6049-e351,190cc intake,looks a lot like a world Windsor head by pictures

Re: SS/CS question.
 

Passenger car engine rule only applies to regular Super Stock and Super Stock GT.
For Modified Class, just needs NHRA Approval of the cylinder head just like all the other aftermarket heads approved for Modified class.

CYLINDER HEADS
V-8 splayed valve permitted in AS, canted or inline in BS,
inline only in CS, and any valve configuration in DS. All heads
must be NHRA-accepted, two valves per cylinder, except
in classes DS, ES, FS, and GS, four valves per cylinder
permitted. Aftermarket aluminum (no billet) cylinder heads
permitted except in CS. Angle milling and/or rolling permitted.
Aftermarket iron heads permitted in CS. Porting, polishing
permitted; header plates permitted. Exhaust port plates
that protrude into port prohibited. Any valve size permitted,
valves may be tilted and/or canted. Combustion-chamber
modifications permitted. The valve cover rail may be modified.
Heads may be cut for larger pushrods and valve springs.
External modifications permitted in port area except for
SS/CS. Spark plug holes must be in NHRA-approved location.

The Superceeded Parts rule does not apply to SS/Modified either.

ENGINE
OEM aftermarket small-block Chevrolet (SBC) engines with bore
centers greater than 4.420 inches are not permitted. Engine
must be same corporate make as body, naturally aspirated.
Displacement unlimited in AS, limited to 366-cid originalproduction
in BS and CS. Engine setback or raising engine
prohibited. Motor plates and mid-mounts permitted. Timing-belt
covers optional. Harmonic balancer meeting SFI Spec 18.1
mandatory. In Section 9A, Connecting Rods, Gaskets, Intake
Manifold, Oil Pan, Pistons, Superseded/Replacement Parts do
not apply in Section 9D. See General Regulations 1:2.