I also made me a hotrod push mower today. I had this nice little lightweight 3.5 hp 20" Troybilt mower that ran but had a bent crank. Seems my BIL had hit a big rock and bent it just enough it vibrated like a .... well big vibrator. My buddy Dean called and said he had this big oleCraftsman 22" self propelled monster that had stopped self propelling and had been put under his deck ohhhh, about 10 years ago.....
So, I deduced that, in true hotrodder style, I would put the big 6.0 "Gold" Briggs on my little svelte pusher. Worked like a charm and looks cool as the motor is physically a good bit larger than the one it replaced. I put in some fresh fuel, changed the oil and it started on the 3rd pull after sitting that long. Ran it into some really tall grass without a hint of slowing down. It was even red, awesome.