The inclination of those valves is very slight, with the inlet being more inclined than the exhaust. The chamber isn't a hemi chamber as you'd expect it. But they must be a reasonably efficient head as they got a bundle of power out of them when they stuck triple Webers on them. 302hp in fact, with people today wringing many more ponies out without supercharging.
The main thing you should be looking for here is cylinder spacing. This sort of thing is an exercise not for the light of heart. A guy here named Laurie Seidl once cut the centre two cylinders out of a Jag twin cam head, welded it all back together and put it onto a Peugeot 403 block. That was fitted with Standard Vanguard sleeves and crankshaft to enlarge it from 1460cc to about 2 litres. It ran in speedway.
Depends on how keen you are on welding cast iron, I suppose, but I think head bolt locations are going to be one of your main concerns.
