Dude, I'm tired of this. You obviously have very little knowledge of the subject. I just pointed out the differences. Take a look a couple posts up. There ARE differences in the head. There are NO differences in the block, except the Boss 351 was selected from the stock of blocks with the highest nickel content. The 351C 4v's were sometimes 2 bolt, sometimes 4 bolt. The Boss was just almost always 4 bolt, but not always.
Like I said, the heads are different, the cam is different, the intake is different, the distributor is different, the rods are different, the pistons are different. You calling the Boss 351 a normal 351C 4v is just plain ignorant, and after my posts, stupid.
Just because you have an old car, doesn't mean you know jack about the rest of the old cars. Quite frankly, I'm feeling insulted that you keep babbling on misinformation. READ my post. There ARE differences in the heads, and the Boss 351 is as different from the 351C 4v as the 1993 5.0 Cobra is from the 5.0 GT.
1974 had NO V-8 option. The top option was the 2.8L V-6 Mach 1 package. 1975 saw the return of the 302, then in 139hp form.
PKRWUD I would agree with the heads being too much for the Boss 302. It's just technically, they do flow better. I know the differences in appearance between the open and closed chamber cylinder heads.
My sources just indicate that all Austrailian 4v's had quench chamber heads, but not all American 4v's did. That's besides the point, as the heads are still technically different because of the machining between the 4v and the Boss. Which is all my original post was made to say.