I am going to use the 1108 cylinder head since that makes life a lot easierOr you might want to take a look at replacing the head with your original head from the 1100cc you have.
Renault 18 engine conversion to fit a Renault 4
For my Vagabond camper I do think that a 1108cc engine is a bit underpowered for the high roof of the vagabond. I don't want to end up standing still with a stiff headwind. I have found a Renault 12 engine with 1389cc and decided to convert it to fit a Renault 4. The Renault 12 has an engine...www.renault4.co.uk
The camshaft for the 1397cc engine runs directly in the cast iron block. I intent to use the 1108 cc camshaft and it needs a bush at the pulley end cos the journal is smaller. My guess is that the pulley end bearing has lots more work to do and it was decided to make make it smaller and use a bush so that it can be replaced when wornWhat do you mean "camshaft bush"?
Keep in mind that, even after fitting the R4 camshaft and deleting crankshaft pulley, cylinder head will need modifying to accept the water pump at flywheel end.