The 302 had a 1.9-1 rod length-to-stroke ratio, which according to some engine builders I know is the optimum ratio. And if you check the hard-core *** sport bikes the lowest ratio is 1.86-1 with some past 2-1. The 1967 ENGINE OPTION Z/28 was a fuelie block-heads-cam (the famous '30-30' cam..called that due to the .030 valve lash on both intake and exhaust) with a 283 3" crank, Then in 1968 they used a 4-bolt main block...ant THAT made the 302 a better engine than the 327-365.
This thread is already spiraling out of control, but just for the record:
* Rod/stroke ratio got a lot of attention in the '70's and '80's but today the consensus is that it's less important than the other things a high ratio interferes with, e.g., longer stroke (= bigger cubes) and a proper compression height.
* The 283 had a 3" stroke but the 302 Z/28 crank was a new forging that had not previously appeared in any 283 and did not appear in any other SBC.
* The '67 and '68 Z/28 302's used 2-bolt blocks.
Conclusion: very little, if anything, of what you wrote supports your opinion that the 302/290 was superior to the 327/365.
The heads on the BOSS-302??? TOO DAMN BIG...period..you had to rev them past 8000 to make real power and you could not do that with a stock 5.15 rod in a street motor like you could in a 302 Chevy. BTDT..broke 7 piston at one time. I firmly believe that had Mark Donahue and Roger Penske raced the Z/28 in 1970 instead of the AMC that THEY would have won the T-A title.
* A stock Z/28 302 made about 330 gross hp @ 6500. If you built a Boss 302 that could rev past 8000, it would be making at least 400 hp. At what level does "real horsepower" begin?
* The Boss piston problem was a supplier problem. It was fixed. It is ancient history. Sorry you were on the wrong end of the deal.
* One man's "firm belief" is just another man's bench racing/wishful thinking. Jim Hall, the Chaparral guy who is recognized as an innovator without peer in his era, ran the Chevy "factory" effort in '70 and won nothing. What could Penske possibly have done that Jim Hall did not do? Have you gone through the schedule, race by race, and found choices made by Jim Hall, where Roger Penske would have done something else, and where that something else would have made a difference? Penske/Donahue did OK with the Javelin in '70, but that was with factory support, an area in which Jim Hall's Chevy effort came up short in comparison to every other make.
And why are we arguing what-ifs about a 37-year-old racing season anyway?
Most builders I knew back when Cleveland motors were in production said you needed 50 cid per cylinder to make that head work properly...and I believe them.
Look, the Ford LeMans 427 was a great engine, better than the same year 427 Chevy mostly due tothe 7/16" rod bolts and good rockers vs. the 3/8" bolts and crap rockers of the Chavy. But tell me why Shelby put mostly 428 P.I.motor in his BB Cobras?......Ford didn't have enough 427's to go around. What is a better engine...a ferrarri 12 cylinder or a push-rod anything built in the USA? Well, the Ferrarri, of course....until you start to need parts. THEN a big inch USA motor with good parts availability and price starts to look pretty darn good. I had the premier sport bike of the early 70's in a Norton Cammando...a much better ride than my old XLCH Sporty, trouble was the Norton sat waiting on parts under warrenty for 8 of the 15 months I owned it.
One other thing..you could buy a 396/375 option in a Chevy for less money than a 289/271 option in a Mustang. How would YOU have spent YOUR money?
* The Boss 302 heads worked "properly" enough with 302 cubes (38 ci/cylinder) pulling on them to win the '70 Trans Am season title, did pretty well in '69 and '71, and won their share of Super Stock events as well. Furthermore, what V8 head wouldn't work "properly-er" on a 400 ci engine than on a 302?
* Shelby American's production car lineup, 1962 to 1970, consisted of Cobras, GT350's, and GT500's. Very few BB Cobras had 428 PI's in them. The 428 PI was the engine in the standard '67 GT500 and the non-KR '68 GT500. SA's marketing strategy was to price them within a few hundred of the same-year GT350. That would not have been possible with a 427. The choice was about money, not availability.
* Shelby beat Ferrari in endurance racing with the 289 Cobra Daytona coupe. 289 and 427 Cobras consistently beat Ferrari in SCCA sports car racing. USRRC sports prototypes were almost all powered by Detroit V8's. In endurance racing from 1965 until the Porsche 917 took over in 1970, the Ford GT beat the Ferrari P3's and P4's consistently, including all those Le Mans victories. Ferrari was a non-factor in Can Am. Ferrari was non-existent in drag racing, land speed racing, and hill climbs, all of which relied on Detroit V8's. Your statement is insane.