'69 350 block with '67 670 heads? doable?

[Custom Tex]

Hi all,

I have a '69 Custom S with a 350 XS block motor. I swapped out the heads with a set of '67 670 heads.

Someone told me that the 670 heads were intended for a 400 or a 428 block with a bore of 4.12". my 350 block has a bore of 3.89". They suggested that the valves might hit the cylinders.

Does anyone have any input on this? The reason I ask, is I had already put the heads on and fired her up before i received this advice. When the motor is idling, I do hear a slight ticking. is this the valves hitting?

what advice would you suggest in this situation?

 

[melsg5]

As you can see from this chart the 69 HO 350 used the same size valves as the 67 GTO heads, 2.11 intake and 1.77 exhaust so I cannt imagine the valves hitting the cylinders. Did you only put on the heads, no cam change? Did you make sure the rocker arm studs on the new heads had no grooves on their sides? Did you torque all the rocker arm stud nuts to the correct figure, 30 ft/lb? Are you using new rocker arms and balls?

http://www.wallaceracing.com/head1.htm

 

[Zimgxp]

Because of the bore differences 3.89 vs 4.12, the bore might shroud the valve a little.