Technical Chrysler/Dodge 400

Not to go against the grain, but has anyone ran a MoPar 400 from the 70's? I read all I could find on Allpar: The last Chrysler big block; basically a overbored 383. Used in all kinds of cars and trucks including police cruisers. I have the opportunity to buy a good one in a clapped out 77 pickup. Any good for a rod, or truck to haul a rod?

 

400 cubic inches can't be bad. You guys are all spoiled. We used to think 300 inches was a big motor.

 

For about the same price as rebuilding the 400 you can make it a 500" and have plenty of torque and tell everyone it's a 361.
440source.com

 

A lot of 400 blocks are used to build strokers. Toss in a 440 crank builds a 451 that is a real good street engine as well as for a real stout race motor. Using an Eagle crank and rods, we built a 499 for a 64 Dodge for NSS.... Ran 9.52@140 first time out. So yes.... They are plenty usable. Benefit too is the low deck block will fit an A body easier than raised block. One downside is some limitations on low deck intakes. We used an Indy tunnel ram.

 

The only substitute for cubic inches is cubic dollars.

 

Not very desirable in stock form for performance usage, actual compression ratio usually measures out to be in the high 7's to low 8 to 1 range, but don't let that deter you, 400 cubic inches is big enough to move any old car or truck.
They are desirable to make stroker motors out of and the low deck height lets them fit in tighter places than a 440.

 

They also have a larger bore than a 440. That is a big plus in my book.

 

4.32 to 4.34

 

Dont know about the rest of you, but in these parts a core 400 is about a dollar an inch ($400, for the math challenged)
Whereas a 440 core will run you about $2 a inch, if you can find one.

 

Look up 451 manifesto ( Ar Engineering) Lots of good reasons to build a 400 mopar or any mopar for that matter. I'm building a 493 now for my 64' Polara .

 

I’ve always wanted to build a high revving 400 Mopar, the stroke is similar to the Chevy 327 if I remember correctly...

Use the forged internals from a 383 along with good fasteners, have it all balanced... seems like a cheap way to have fun...

 

Should be excellent for a rod, or a tow vehicle. You might look up Don Dulmadge's Old Reliable build for the most bang for the buck. They are still popular, parts are available, and they mate up to the 727 Torqueflite

 

Excellent engine!
It just needs compression,,,,about 8 to 1 from the factory.

Other than that,,,they are powerful and dependable.
Go for it!

Tommy

 

The 400 is a good engine. If it’s for street use just find a pair of 906 or equivalent heads, purple cam and a Mopar or equivalent dual plane after market intake. With flat top pistons that set up pushed my 4,000 lb car into the 13s with street tires.
Not a rocket but it was fun and sounded great.

 

It should have 452 heads on it if there not cracked with a pocket port and 2.14/1.81 valves will flow an easy 525 horse and 550 ft tq with a 9.5 cr 451.

 

Thanks for the quick and useful responses.

 

As many previous replies said, the 400 has a larger bore than the 440 does. It will also fit a stroker crank and enable easy 500 cubic inch engine. The 400 blocks are what are used as basis for most of the BBM stroker kits.
If you just want it for a cheap engine to use as-is, the biggest issue is the low compression and wimpy camshaft since it was a smog era engine. Swap heads and cam and it will work good as the base 400 inch size.

 

What is there? .020 difference in bore size? Or so. Don't think I would get to involved about that. I think intakes for the raised block engines are more plentiful than the low deck

 

Whats also nice nice about the 400 block is the amount of material in the webbing. I'm building a 440 based stroker but around here the 400 blocks are getting harder to come by because so many where crushed and now the mopar guys caught on to 451 and 470 's are are starting to hoard them. If you do build one take a look at trick flow 240 and 270 heads and even their top end packages. Mopar wedge motor parts development has been late to the game but it's finally getting some attention from Trick flow, Edelbrock, Indy, Hughs ect.

 

Around here the right 400 block is $500-600. And used for stroker's. But if you're on a budget. They make ok power as they are with just a set of pistons. And the normal hot rod parts. I will have to look at some old notes. But I think you can use .030 over low comp 440 pistons (1.920ish if I remember). Have the block honed to fit and end up with zero deck. Gene.