The 69 Pontiac still has the Pontiac Engine, and no it wouldn't bother me to put a Chevrolet 383 stroker in it, which was what I was planning on doing anyways, but I can get a stroker kit for the Pontiac engine for $1200 dollahs. When all the porting, polishing, and stroking is all said and done... It will probably cost somewhere around $3500 dollahs.
A 32 roadster is different, many people have been putting small block chevys in them for years. Does this bother me?? Somewhat, because you loose the GM vs Ford rivalry. You mesh 2 opposing companies into one vehicle. You just loose the pride of beating the other company thats all. Putting a GM motor into a Ford is just sucking up to GM, thats it, and you can push a 4.6 way farther than 600hp. Alas, a 32 roadster is a HotRod, and I would expect to see some company mixing in the process. No, I personally wouldn't ever put a toy' motor in a 32 roadster, but you can do what you like. I'm not against imports, heck if you want to talk going fast cheap I'd just buy a sport bike and forget about it.
I had a friend that built a 69 Nova, and put a 800hp 502 FORD engine in it. The car ran 8's in the quarter mile. Awesome it was, but I personally was not fond of the GM+Ford mesh. A pontiac is a GM, a chevrolet is a GM, so engine swaps between the same company does not bother me.
You company mesh GM, Dodge, and Fords hottest factory cars, and I'm all but in disgust for the swap. A GT40 with an LS7???? Uhhh what is the point in sucking up to the enemy??? Or putting the supercharged 5.4 into the Corvette??? To me it's extremely dumb, but if you want to do it go ahead. Sometimes you can save money, but in the end, it's still wrong no matter who's opinion it is. The type of wrong I speak of is not deadly sin wrong.... but like an antelope eating a lion wrong.