You've got 1978 in the thread title, and 1973 in the thread body. Those are totally different cars other than most of the name and the manufacturer. It could probably be made to fit either one, but as @jozsefsz said, the '73 would be a lot easier out of those two.I was wondering if a Chevy 305 engine will fit in a 1973 Mustang?
1973's not a II, you might wish to ask in another forum. Though your title states 1978 so I'll assume that. A 305's a few inches wider than a 302 so it would be a very tight squeeze in a II (and finding some very narrow headers may also be a challenge) without more substantial modifications. A 1973 has a substantially wider engine-bay. Then you're into oil-pans, transmission configurations, etc. I'm sure anything can be engineered to fit, but as you're a new member and I know nothing about your background, and you're asking a question best asked by doing a lot of googling and measuring, I'd say no it definitely isn't going to be an easy fit. If you have a 305, sell it and pick up a nice H.O. 302.
The Chevy 307 was just fine. It was a 327 crank stuffed in a 283 block from the factory. A friend in high school had a Chevelle with one.I dunno, from what I remember the 307 was a complete turd compared to the 305?
The best thing about a 307 was that the Olds 350-455’s bolted up in it’s place.
I think the same can be said for the 305, but with 350-400 Chevy blocks.
If you are not trolling, selling the 305 for a 302 would be an easier starting point and should be easier to get power out of.
Now if you want to be different, go for it. But why not start with a 45 cubic inches, or a 383, both with better heads?
This is true, but if you didn't need insane horsepower, a G-body with a 305, quadrajet, computer-controlled distributor, and TH200-4R transmission could get phenomenal gas mileage. Our '83 Bonneville wagon regularly got 22-24mpg as a highway commuter. For a car the shape of a brick, the size of a small tank, and heavy as hell, that's impressive. It was just horrible on power, and not worth building for performance (though a 350 or 383 swap would've been fun if I'd been smart enough to keep that car).Ford was not the only company that made some poor engineering choices in the early 80’s trying to meet fuel efficiency and emission standards.