I'm building a 2056 Type IV for a 912 and I'm wondering what people think of putting stock 1.7 heads with bigger valves on such an engine. Seems like the top end would be restricted because of the small port size.

You could just port them out to remedy that smaller intake.

Geoff

you wwill also have to get the 1.7 heads flycut to allow for the bigger cylinders/pistons

1.8 or 2.0 heads will save you money at the machine shop... on shoptalkforums for example... 1.8L BUS heads are a favorite for 2056 engines... they need very little porting, no flycutting and are CHEAP!

Yes the 1.8 bus heads are cheap but usually have had a tough life. Find some 914 1.8's if you can.
Geoff