Big Block vs Small Block, a Cobra quandary

[KevinM]

Bill,

I'll take a somewhat rambling shot at this, giving my reasoning as I go.

If authenticity is important, then obviously a 427 or 428 FE is the choice.

With that out of the way, we can look at what is the best engine for different uses. My interest has always been street driving, so I will let someone else talk about track use.

Shelby used the engines he did because they were what he could get. He originally wanted the smallblock Chevy and only went to Ford after Chevy turned him down because they didn't want another car to compete with the Corvette.

If Shelby had been able to get the engine he wanted, the 327 Chevy, there never would have been a big block car. The Chevy could be stroked to 377 CI and made 485 HP in that form (As used in the Grand Sport Corvettes). It would have been all he would ever have needed without the weight, heat, etc of a big-block. (I think it is very instructive that Duntov chose the smallblock for the Grand Sports and not the big-block Chevy. He understood the problems with excess engine weight).

The Grand Sports pushed Shelby into needing more power, and the only choice he had with Ford engines was the 289 or FE. The FE Shelby originally planned to use was the all aluminum NASCAR 390. In fact, that's what Ken Miles used in the first car at Nassau race week. For a car intended to be a race car, it was a pretty good engine, and that's the engine the coil spring chassis car was designed around. Unfortunately, when they actually got ready to build the car, Ford told them they would get the iron 427 instead of the aluminum 390. So Shelby got stuck with an engine he never intended to use.

If we look at what Shelby did for his own car a couple of years later, we see that when he had his personal 289 Cobra re-powered in the early 1970's, he chose a Boss 351 for it.

I think that if the 351 had been available in 1965 Shelby would never have used the FE. Especially for a street driven car.

I think the 351 Windsor with modern aluminum heads would be a much better choice than the FE if you actually want the best possible combination for real world driving.

So, to sum up, the FE if you want to duplicate an original. The 351 if you want the best car for street use and the engine Shelby would probably have chosen if it had been available.

Kevin