How well this goes will depend on the compression ratio and the cams fitted to the head. 44 36 valve sizes are unlikely to be a problem. If it has GC cams they will have the number on the end under the cam box end plate and they will be timed to marks inside the cam box that need adjustable cam wheels to install well . A higher compression ratio is often needed to get the best from high lift longer duration cams. You need to take care if you have higher compression pistons and high lift cams and check clearance by a dry build check as detailed in GCs books. A real GC head will have the number stamped on it and Guy is likely to have a record of the build.
Make sure you know how you will fit a distributor if you are thinking of an exhaust cam driven item the cam must have a drive for it and the cam box a mount for it. Beta Block mount is fine as long as the inlet manifold misses it.
Eric
A friend owns the head which he got built for his Monte a number of years ago but never fitted.
It comes with a set of 40 IDF carbs and manifold but I imagine I'll need a Beta manifold.
I just wanted an overall feel for the idea before I brace the subject of seeing if he wants to sell
Thanks for the invaluable info as usual, everyone