Engine replacement for 30 year old inline twin Briggs 16hp. anyone replace with a new model?

replacement for 30 year old inline twin Briggs 16hp. Anyone replace with a newer engine model?

Please post the model, type and code numbers from your engine. I've replaced many, depending on the condition of the unit and the kind and cost of the Briggs engine.

The engine isn't made anymore. It is an inline, opposing piston engine. It has a horizontal shaft that sits high. This could be a PTO connection problem. It is wider than the newer twin v piston engines, the size may not allow a direct bolt in replacement. The engine model number is 4022437 0705 01. Parts are hard to get. I would love to install a new Kohler, Honda,or Kawasaki engine into this lawn mower. Can it be done? It would be a good thing for my 1986 Cub Cadet mower.

Any engine can be replaced with any other, it all depends upon how much you want to muck around with it.
It is a lot easier to mount the motor on spacer block to raise the shat than trying to get it lower.
That is the answer to your bolt hole problem as well.
Weld studs to a plate that fit through the engine mount holes then use a nut and do the same for the holes in the mower.
The V twin will be higher so you will need to modify your hood ( hot rod mower ) or run without it.
If the mower drives off a stub axle on the flywheel then you can fit almost any engine .
I use this site https://www.smallenginesuppliers.com/html/engine-specs/engine-specs.html to look up engine dimensions.
I also buy a lot of engines from them that are surplus at up to 75% discount.
Small Engine Warehouse is another good source and some one from here put me on to The Surplus Center and I have bought some really cheap stuff from them.

Thank you Bert.

I thought it could be done. All I needed to hear was that someone has done it. I'll put a picture of the mower up when I get it finished. You 're a good man Bert