Looks like my 226 in the 48.

 

There were conversion kits back in the late 40s and 50s to install six and eight cylinder Ford truck motors into N series tractors. Funk was the most well known and I think is being reproduced. You are correct, that is an H series six installed in a stretched Ford tractor. Adding power does nothing for the gearing and lack of weight on the rear wheels....

 

I had an 8n years ago. This one is a Funk conversion. I've even seen one with an 8BA V8 in it before. The brakes on the 8n were poor at best.

 

The neatest 8N conversion that I have seen had a V8 60 engine in it. The 60 is small enough that the hood and axle fit in the stock position.
Mark