hhhhmmmm... I'll have to ask my dad why he and his brother had to beat out the towers to get it to fit. Maybe they were using the wrong headers. This was back in the late '70s too, so probably not as much aftermarket support for this swap yet.
Oddly enough, I think those headers were available right away, becuase one of the magazines used swap headers to put a boss 302 in a Maverick way back in either 69 or 70.
Your "car buff" friend is "car stupid". Even the original Boss blocks were not stamped "Boss" on them anywhere.
Just got an email from the old man. My uncle's car was '70 so I was wrong there. The first installation used the stock cleveland manifolds, so that might explain the clearance issue, maybe not. He swears up and down it wouldn't fit without beating the shock towers, but he was also 17 at the time and you know how much fun it is to use the torch and sledge at that age. Then they bought the the headers. "The headers we used were multi pieced. You installed the engine and part of the headers, then fitted the remaining pipes and bolted together using over lapping tabs. I don’t recall them cross over, but they may have" It's been 36 years since he's seen this car so his memory is a little rusty. Anyway, it's always fun to talk cars.
The first Boss 302 in a Maverick was done by Doug Nash, the shock towers were not cut. Brooklands Books reprinted some of Hot Rod's early articles on small block fords and in the one on Boss 302's there are 3 pictures of the Nash Maverick install, very clean job. The same company has a book on 351C engines and it has a picture of one of the 2 first Pro Stock Mavericks ever built. The cars were built by Dick Loehr and Ed Terry and had 366" Boss motors built by Hank the Crank. The book states that after the bugs were worked out Ed Terry's car ran 9.83 at 138.96. Not bad for an all steel car with mostly stock engine and drivetrain parts.