1965 engine crate engine

[BK911]

Hey guys,

Getting ready to pull the trigger on a crate engine for the '65 stang.
Mostly decided on a blueprint engine, but not sure which one.
They have a 235, 300 and 390 hp engine for ~$3300, 4500, and 5500, respectively.
Looking at the dyno, I am leaning towards the 235hp engine since most/all my driving is below 4k rpm.

What do you guys think?

[BK911]

Oops, supposed to say 1965 Mustang crate engine

[VincentVega]

Assuming you never get the urge to wind it up, yes go with base. I'd go with +1 assuming it idles ok and uses pump gas.

[Tervuren]

Well, personally I'm going to want the higher revving engine.

[pwd72s]

I think you're wise to consider the actual driving you do when making the selection.

Since I only drive street/highway now, I really appreciate the flat torque curve of the 4.6 in my '09 Bullitt Mustang. Horsepower numbers alone are great for bragging rights, but they don't necessarily translate to pleasant driving.

(edit) The numbers shown don't tell the tale of the internals used in each engine. That might also figure in, with me opting for forged or hypeutectic pistons, forged crank, better rods, etc.

[pavulon]

Am a fan of displacement (or turbochargers). Fat powerbands make for pleasurable driving without much thrash. Low thrash tends to make for fewer problems or repairs.

[masraum]

We don't have all of the factors that need to be considered.
How much of a factor is co$t?
What transmission?
What rear gear?
Can the rest of the car handle the power in the 390?
etc...

Based on the information that we do have, I would say that you should NOT get the 300hp version. It's got less power through a lot of the rpm range that you'd be using.

But if you compare the 235 and the 390, then you can see that the 390 always has AT LEAST the same power as the 235, but sometimes quite a bit more. So if you ever want to use more, you can. And even with the 390, you can still short shift at 4k if you want. If the cost increase isn't an issue, then the 390 will potentially be more fun if you ever do want to dip into the loud pedal a bit deeper.

[JackDidley]

For me, more is better. Auto or stick? With an auto a 2500 stall will overcome any lack of power down low and will make for a fun ride.

[GH85Carrera]

I went through a similar decision making process when I was in the market for my replacement engine for my El Camino. It was all how much HP do you want to pay for. As the Elky is my daily driver, a high HP engine was not seriously looked at.

In the end I bought a base 350, brand new not rebuilt, crate engine from GM. The good news for me is small block engines are super cheap. I had a new 350 delivered to my driveway for $1,700. I swapped it into place of the OEM 305 over the long Thanksgiving weekend.

I will answer your question with a question. Is the car to be used for just cruising or do you see you wanting the HP?

How are the brakes? Will they handle the higher HP? What about the transmission and driveshaft? The rear end? More HP to the rest of the drivetrain will cause more problems with all the other components. If your next step is to NEED bigger brakes, how far away is a new rear end, driveshaft and the rest.

[tabs]

Is this a Ford 289 cubic inch motor?

[Sooner or later]

As others have said. Trans type, gearing, expected uss, brakes, cooling system...

Is this a period correct looking build or a restomod?

[LWJ]

A 65 mustang may flex like hell with 390 hp twisting it. Meaning, the bigger engine may mean sub-frame and different / modified axle.

A thought.

[Sooner or later]

Originally Posted by LWJ

A 65 mustang may flex like hell with 390 hp twisting it. Meaning, the bigger engine may mean sub-frame and different / modified axle.

A thought.

Good point. I had a poppy red fastback K Code taken up to Shelby spec. It was a handful.

[Scott Douglas]

I agree with Steve (Masraum). The 390 will be more fun to drive and just because the power is there doesn't mean you have to use it. I wouldn't necessarily want to have to pay for the gas it would use, but that's why I drive a Honda.
Remember, you can feel torque, but not necessarily HP.

[Sooner or later]

A 65 Mustang weighs about 2500 lbs. With the 390 horse that is about 6.5 lbs per hp. That is Hellcat territory and overkill without other major mods.

[BK911]

Wow, thanks guys!
Bone stock with auto trans.
Not sure of gears.
Drive to work once a week, family cruising, nothing needing 390hp!

[masraum]

Originally Posted by BK911

Wow, thanks guys!
Bone stock with auto trans.
Not sure of gears.
Drive to work once a week, family cruising, nothing needing 390hp!

235 it is which will still probably be more than it had originally.

[Jeff Higgins]

If you look at the dyno charts, you will notice that the two more powerful engines don't give up anything to the lower power engine down low in its power band. They make more power across the board. They do not appear to be "peaky", sacrificing low end power for their improved power higher in the rev range. In light of that, I would go with the most powerful motor. You don't have to use it, but it is there if you want to use it.

I would also be quite interested in the differences in internal parts. Cast vs. forged crank, pistons, and rods, quality of valve train components, etc. I would assume the more powerful motor uses higher quality parts in those areas. I think that would lead to better longevity, especially if you hardly ever push it.

Anyway, I would rather have it and not want or use it than someday want it and not have it. There isn't much of a price difference to get the better equipment today, but it would get spendy to try to get there tomorrow from a lesser starting point.

[asphaltgambler]

Good answers / questions above^^^^^^^^^

[masraum]

Originally Posted by Jeff Higgins

If you look at the dyno charts, you will notice that the two more powerful engines don't give up anything to the lower power engine down low in its power band. They make more power across the board.

I think the 300 does actually make less at the lower rpm range. It's just that the low power model starts with power numbers at 2000rpm and the middle engine starts at 2500. I cropped the two images of the 235 and 300 to show 2500-4000. The low powered model is making more torque for quite a bit of that range.
300 vs 235


If you do the same comparison for the 235 vs 390, then you can see that the 390 makes as much or more torque at every rpm than the 235.
390 vs 235

They do not appear to be "peaky", sacrificing low end power for their improved power higher in the rev range. In light of that, I would go with the most powerful motor. You don't have to use it, but it is there if you want to use it.

That was why my initial recommendation was for the 390. He can short shift all he wants, and I suspect the fuel economy and fun will be the same based on his right foot.