400 stroker, 440 6 pack, or 440 stroker?

[TexasRoadRunner68]

I will likely be picking up a 70 RT track pack this month sometime. It comes with a date correct 1970 U code style 440 and numbers trans and Dana, however I also have a 400 block I intended to do a stroker build on. Am I going to regret not keeping a 440 in the car?

I know the 400s have beefier mains and rev quicker, while allowing more hood clearance for taller intakes. The 440 would be more correct in the car. I could either do a six pack setup on it or stroke the 440, or just build it as a 440. I’m sure building the base 440 would be cheaper since I can reuse the crank, however Hear you may as well get newer lighter rods than the 70 6 pack rods.

It’ll be a street car, and Id hope for 500-600 hp and 500-600 ft lbs. I’d like it to survive as well lol. I hear the single 4 bbl carb with the right intake is better performance wise than a 6 pack and probably cheaper, but they are just cool. I would probably get it running and drive it a bit before doing the metal and paint at a later point. I just want something fun that has that big cam big block mopar sound. I’m sure 500-600 in a street car is plenty. Any words of wisdom from those with experience?

 

[diesel_lv]

This is a 383 stroker, but a 400 would be about the same. 500+ is very easy. That would leave the original 440 intact for later.
https://www.google.com/amp/s/www.mo...ysler-383-big-block-mopar-for-the-masses/amp/
But 1st, you need to figure out what you want, not what others recommend. Gotta make those big boy decisions on your own.

 

[TexasRoadRunner68]

Totally. The 440 is date correct but not numbers matching. Ideally I’d like 650-670 hp, I have seen it done on some super well built motors…but I don’t know how realistic that is. At that power level, how long will a 440 survive before you start getting cap walk or cracks?

 

[6pktgo]

I have a very mild , 70 coded block ,440 six pack in my Charger. 425 hp & 530 ftlbs of torque at 5300 rpm. 390 hp on the center 2 bbl carb alone!! When backed with Hemi 4 speed & 410 Dana, it's a fun car to drive and pulls very hard.
Doesn't matter where you go ,the six pack setup always draws a ton of attention!
My nickel's worth, because up here we don't have "my 2 cents worth ", anymore !!

 

[Jerry Hall]

As it looks like you don't have the matching engine, my personal opinion is to keep it as built. From what you said, I don't think you are moving toward a restomod, therefore it would be worth the most as original to future owners. You can do a lot inside a 440 to meet your HP goals and still have a fun and enjoyable car. In the end, it's your car so do what you want.

 

[Curiousyellow71]

Since a r/t only came with a 440 I would not do the 400. A 400 at the power levels your talking isn't really much of any gain then building a 440. 600hp just use main studs.

Stroke the 440 with a 6 pack..
...not on your list.

 

[IQ52]

I think what I would regret is letting someone else tell me what they think I should do with my car and not doing what I want to do.

 

[4mulas]

I know the 400s have beefier mains and rev quicker, while allowing more hood clearance for taller intakes.
It’ll be a street car, and Id hope for 500-600 hp and 500-600 ft lbs. I’d like it to survive as well lol. I hear the single 4 bbl carb with the right intake is better performance wise than a 6 pack and probably cheaper. I just want something fun that has that big cam big block mopar sound. I’m sure 500-600 in a street car is plenty. Any words of wisdom from those with experience?

For all these reasons I’m VERY happy with a 400/440 crank for 451cu combo and it’s performance.
Easily achieve 500+ hp with heads and a cam, headers etc……. The extra almost one inch hood clearance is nice too. Revs quick!

Just make the car that you want as well. Don’t worry about what other people think and what is more correct. From the sounds of it the Original motor is long gone any way.

Good luck

 

[68 HEMI GTS]

You won’t regret either as a stroker. I run a 400/512 in my car with a six pack. No matter what you choose it needs some good flowing heads.

 

[Steve009]

I’m currently finishing up a 400 stroker engine (470ci). Using TF240 heads and a single plane TF intake well over 600hp shouldn’t be a problem for you with a 470 or 512 stroker build. It’s not cheap to build but that power is doable. If I were you I’d take the 440, do a 500ci stroker and use the 6 pack set up because it’s cool. Yes a big single carb will make more but a 6 pack is just cool.

 

[68 HEMI GTS]

I’m currently finishing up a 400 stroker engine (470ci). Using TF240 heads and a single plane TF intake well over 600hp shouldn’t be a problem for you with a 470 or 512 stroker build. It’s not cheap to build but that power is doable. If I were you I’d take the 440, do a 500ci stroker and use the 6 pack set up because it’s cool. Yes a big single carb will make more but a 6 pack is just cool.

View attachment 1216956

you’d be surprised how well the six pack holds its own. I’ve ran a bunch of different combos on my car. The six pack ran identical to a ported TM6 and a 1050/4150. The time slips were identical. The only combo I would say was stronger was an mw ported Indy single plane and a 1050 dominator.

 

[RemCharger]

They should really make a plastic dummy lid that looks like a complete 6 pack induction system you could just slide over top of your engine.
Kinda like new cars.

 

[451Mopar]

Totally. The 440 is date correct but not numbers matching. Ideally I’d like 650-670 hp, I have seen it done on some super well built motors…but I don’t know how realistic that is. At that power level, how long will a 440 survive before you start getting cap walk or cracks?

Why is 650-670 Ideal for you?
What cylinder heads are you going to use?
Either block should be fine for 600 HP street/strip use with main studs and light weight pistons (Just my opinion.)
The 6-pack is very good for performance and looks great. Only real down side is having to tune 3 carbs that are harder to get at.

Here is what I found out doing some of my projects:
If your real goal is power/performance (over 600 HP?) then don't expect it to be stock looking unless you have deep pockets.
Stroker kits are pretty good value for the money, but are not a drop in and go item. Check everything.
Stock heads can be made to work, ask IQ52, but the aluminum heads are likely a better value.
The 440 source heads with some porting would have the correct look with the 6-pack.
If you start adding non stock looking parts like aftermarket valve covers, air filters, and such then there is no reason to try making the engine appear stock, so just use something like a Trick Flow head.
If looking for > 650+ HP, Just start with a max wedge port window head, and large aftermarket intake. Then maybe use the 400 block too.
If you want all the modern stuff / pro touring type setup, it is likely that a Gen III hemi swap will be less expensive.
All the combinations I am thinking of would not use 6pack rods and would be internal balanced, so a new damper would be needed.
A good build cost a lot of money, a bad build still costs alot of money plus what was originally spent on the bad build, plus wasted time and effort.

My vote would be a 4.25" stroker 440 for appearance with the 6-pack, or in a 400 block for performance and ease of fitment.
The 4.25" strokers are pretty easy to build and retain the internal oil pickup.
There is also a large assortment of shelf stock pistons for this combination, so it is fairly easy to get one for the compression ratio you want.
This give a good base short block for many power combinations.
The top end parts of heads, intakes, and such would depend on how you will use the car and personal preference of power, appearance, maintenance, plus the cost(s) of parts, fuel, and maintenance.