Here's the thing: rockers are all over the map. Some guys have measured generic eBay "1.25" rockers and found them to lift almost 1.4:1. I bought a set of CB's "1.4" rockers that measured out at 1.47:1.
The stock VW cam is split lift and duration (the intake is different than the exhaust). The specs I'm finding claim a stock cam lifts .297 on the intake at the cam.
If Kaddie Shack's "1.4" rockers really did lift 1.4:1, they'd be bumping the intake valve .4158", which seems to be in the range for single valve-springs. If they measure out to 1.47:1 (like mine do), they'd lift the valve .4366".
The stock cam's duration is 224*/228* and 210*/215* at .050" (intake/exhaust), which is very, very mild.
It's an interesting question. According to a cylinder head chart over on TheSamba, a VW 043 dual-port cylinder head flows 109 cfm at .400" lift and 117 cfm at .500" lift. According to the Wallace Racing cfm/hp calculator, the stock heads should support 109 hp at .400" of lift. This is clearly poppycock, but it makes me tend to believe @ALB's link.
I'd use 1.4s with a stock cam and heads. What's the worst thing that can happen? Broken valvesprings are cheap and pretty easy to change.