The 273 cannot by any stretch of the imagination be called "long stroke". It was oversquare, bore 3.625, stroke 3.31. It had exactly the same stroke as the 318 and the 340.

The 273 piston was so light that the factory used special heavy pins to get the bobweight to the same value as a 318 so they could share the 318 crank and rods.

The 273 liked GEARS. Someone mentioned 4.56s, that's what I mean.

It's true, I have been given three 318s over the years. And it has 45 cubic inches more and will rev the same as a 273.

It would be a fun project to turbocharge a stock 273. You could get your tuning experience with a throwaway engine. Then when you'd learned how to turbo an engine, you could move to something bigger.

My dream for a 273 would be 3.58" crank, 30 over for 300 cubic inches. You can easily take 200 grams off each piston/rod combo. If you have to buy custom pistons anyway, then it costs little to stroke it. So maximum 500 gram pistons and 600 gram rods. The smaller bore has less octane requirement so I'd go for 11:1 with a decent aluminum head. I'd use a Perf RPM and 750 Holley, headers and a mechanical lifter cam. The cam doesn't have to be overly large but it does have to rev easily. Bullet has lobes that are designed for this.

Yup, you could do the same thing with a nearly stock 360. And it'd cost a heck of a lot less. But strip out a '68 Dart and add a 5 or 6-speed transmission and it'd be a lot more fun on challenging roads.

It's your money, do what you can afford.

R.