Patrick from Patrick's Antique Cars is very knowledgeable on cams for the 235. I would call him with questions.
The M4F is a fairly mild cam, we used to call it a 3/4 race cam. With it in a 235 you will give up a little bottom end torque. You will gain some in the top end. I put this cam in my 235, which is otherwise stock. I can set the idle at 500 rpm and have had the engine turning 4,500 rpm.
A good friend has a full-race cam in his hot 261. I don't know if it's the F290. He did serious work to the engine. Bottom end balanced, head professionally shaved and ported, Unilite distributor with a MSD6 box, cast Fenton headers and dual Holley-Webers on an Offy intake. He has the idle at 600 rpm, it is a little lumpy, but not bad. This engine has spun around 6,000 rpm while doing burnouts. It would be way to much cam for an otherwise stock 235.
