geomac, in my personal opinion there are worthwhile arguments for not getting another Intek engine. If you search the internet you might find multiple reports on some of my reasons for feeling that way, but of course it is up to you.
There are two mainstream approaches to replacing your Intek with another Briggs product: either the horizontally-opposed 40-46 cubic inch twin cylinder side valve series (model numbers beginning with 40, 42 or 46) or the single cylinder OHV Vanguard 17 hp - which is the largest single cylinder model they make. The key issue is checking that the opposed twin will fit on your mower, since it is a couple of inches taller than the single cylinder Intek. There also has to be room for the different layout compared with the Intek. The main attraction of the opposed twin is that it has been around for a very long time and one should be available very cheaply if you look around carefully. The engine has a good reputation for reliability, durability, and smooth operating. The single cylinder Vanguard has a very similar layout to the Intek and will probably fit on easily, but is likely to cost you five times as much money as the opposed twin.
