[JSeery]

To me it depends are what you are calling apples to apples or equal comparison. A stock 265 Chevy back in the 50s pulled from a salvage yard had around 162hp, almost double a stock flathead. And very simple inexpensive mods could reap fairly health increases in hp. What I was refer to is the cost to get any kind of performance out of a flathead requires a much larger layout of money to even dreaming of getting into the range of a stock 283 Chevy or 5.0 Ford and about anything else. If you put the same effort and money into any of the later OHV engines the returns are far greater than an equal amount poured into a flathead. I love flatheads for what they are, but to say they are as cheap to work on as a later engine does not come anywhere near my experience!

Jerry Livingston here in Wichita KS builds flatheads for sell at around $2300 for a late model ($2600 for an earlier engine). But these are long blocks which require a lot of additional parts to get running. If you start talking any type of modifications the price starts climbing quickly.