[Rar_421]

Has anyone compiled a list of these heads?, specifically the valve seat angles?,I know the 17's are 45 but was wondering about 14's?

[steve25]

I don’t recall the 30 or 45 intake valve thing starting until 69 and a # 14 casting is a 68.

[Cliff R]

1969 #46's have the small valves and 45 degree intake seats. They are "sleeper" heads. Without even touching the ports with a grinder or sanding roll we stuffed a set on a 455 shortblock when the SD Performance heads/custom roller cam weren't going to make it in time to get the engine in place for Norwalk one summer. All I did was tap them for screw in studs, "touch" the valves and seats with my valve/seat grinding equipment, and tap the end bolt holes for headers. Set them up with stock retainers and Crower 68405 springs, a used Crower cam from the parts room, stock HEI and recalibrated Q-jet.

It went into a 1981 Firebird close to 2 tons, with one of my TH350's and Continental converter. I was hoping for/expecting mid to high 12's best case scenario. Right offthe trailer it went hight 11's at 112-113mph in the heat of August!

So much for needing big valves or 30 degree intake seats or even any head porting/port matching to make respectable power and vehicle performance.....

[Rar_421]

Originally Posted by steve25

I don’t recall the 30 or 45 intake valve thing starting until 69 and a # 14 casting is a 68.

Guess I was wrong on the 17's,could of swore I read on here a while back they were 45,maybe mixed them up with 46's Cliff just posted about

[steve25]

Well I could be wrong as I don’t have a set of 17s to look at anymore and I am not really 100% sure.

Maybe someone with a set of 17s will chime in.

But yes. 45s 46s and 47s could be one or the other and to this day I don’t know why the factory did such, especially seeing as 350 two bbl motors had a cam of well less then the normal.406” lift.

I would think that they would want a 30 degree seat valve for those motors.

[242177P]

Originally Posted by steve25

I would think that they would want a 30 degree seat valve for those motors.

Would bore shrouding have been a concern? (3.875 vs 4.12)

[steve25]

Well yes, maybe the factory was playing around with that in terms of a 350, but all the 1969 400 2 bbl motors got the small valve head and one or the other seat angle intake valves, and even that same 254 Cam also.

[54nomore]

I can confirm that the #15's on my 68 Catalina have 30 degree intakes and 45 degree exhausts. I would be very surprised if the #14's were any different, aside from the bigger chamber.