LongBox55 is right. The reason for going to overhead valve was better breathe ability. Flat heads didn't breathe as well. If I am not mistaken the T head had a valve on each side of the cylinder. An F head had a valve in the block and one in the overhead. Military jeeps had some of those. They ran good. Nothing like a GM bolt though. BTW, I went to the Show and Shine this past Saturday and there were about 5 bolts there. All the rest were V things. 55-59 Chevy pick ups were there and many classic cars and trucks including a Diamond T. One bolt was in a 41 Chevy 2 door car with a 292 matched to a T-5 trans with 3:00 gears. Has a 500 cfm Edelbrock 4 bbl, balanced and cast iron headers. Sounded great and gets 20 mpg in town! Had chrome valve cover and chrome pushrod covers. Two bolts were in Chevy pick ups. They were 235s all rebuilt. It was nice to see at least a couple of inlines there. About 200 cars were there. Great show here in Medford Oregon. Just a nickels worth. Henry
