Originally Posted by gearheadslife
you cutting the top of the bore to unshroud the valves with heads with bigger valves, or just letting them smash into the cyl wall/deck
Not a problem with using stock size 1.94x 1.50 valves in the 350 heads, on a 305 engine. They don't touch the cylinder walls.
Whether the valve is in fact shrouded is a relative thing. Event hnou the larger 1.94" valve is closer to the cylinder wall than a smaller valve,,, It still flows a LOT MORE AIR than the stock as cast 305 head with its tiny 1.72" valves does.
The area where the intake valve is closest to the cylinder wall is a low flow area any way.
The air flow is concentrated towards the spark plug as it enters the chamber, not towards the cylinder wall, which would be a 90deg turn.
The 1.94 valve gives a net over all flow increase, especially if/when the head is ported. Shrouding is not a issue on this motor using a 1.94" valve. Valve to cylinder wall clearance is not a issue with the 1.94 valve. It is closer than the stock valve is but not a issue worth bothering with. No I will not be notching the cylinder bore.
But a 2.02 valve would be different.
No dyno test either. It is very simple straight forward low cost build. The car's performance will tell the tale.