Hey all,
My daughter is looking to build a 400 for her 72 SWB truck; we are looking for some ideas for the motor build,
the 400 is a 72 Steel crank engine out of a 4 sp RR , its going to need to be bored and decked , now she can't stroke it only an over bore .Truck is manual brake and steering, and a 4speed
She's looking for something on the edge of street ability single 4 bb.
Any ideas on heads (906,452,516)

she got herself into a bet with a guy who has a 396/402 BB chevy C10 swb truck and they're going to race each other at In June to see who's quicker, both trucks have to be able to travel 35 miles to island dragway
Both have agrees not to spend more then 5k, and each must use period corect block and heads.
all Ideas are welcome

First decision is if you're going to stay with pump gas or not. Once you decide that then you can oder up the pistons and go from there. Best bet is probably the Edelbrock RPM heads rather than cast iron. They'll be cheaper in the long run and they drop 50 lbs off the nose. Put a healthy flat tappet cam in it like the Mopar .590 solid and run a Victor intake with a 850 DP carb. That should give you some decent power.

Nitrous!

Throw a set of LY (440 length) rods in her and a set of flat tops for 10:1 and try to get at least 260cfm out of the heads by .450 lift, with an inexpensive MP 528 solid cam, a Performer RPM/750 DB and a set of cheap hedmans it will be a very good running motor with a nice small block style RPM ceiling. Have lots of fun with it!

I agree. Long rods, short pistons. Diamond makes shelf pistons for the combo. KB may also. As for a cam, I like rollers myself. Chet Herbert's shop can grind you nice street roller for less than a shelf piece. Roller lifters are affordable at about $220. Get on the phone and you can probably get the cam, lifters, and bronze drive for $500. Get a used set of sintered iron rockers for another $100. Edelbrock RPM's and a M1 or victor. Victor intake may not work unless you up the compression, cam, head flow, and rpm.

Good power will be made with everything working at a higher rpm than your typical 440.

Why can't you change the crankshaft? Throw in a 440 stroke crank, stock length 400 rods, and matching KB hyper pistons. Ported heads and cam ground to match the flow sheets and go. She could say it's got 400 rods and new KB pistons and a stock crankshaft that's been ground to clean up the journals. Wouldn't be a lie. The short rod will make for a torquey motor.

You can build a pretty nasty 451 for under 5k. & it will make substantially more power than just about any stock stroke 400. Having a forged RB crank cut down is only going to cost a few hundred more than cleaning up her existing crank. I'm assembling one now, and have a total of $4200 into it, including stealth heads! (BTW, I don't know that there is such a thing as a forged steel crank 400? I thought all 400's were cast crank motors)

My father has the 400 motor build to perfection...a 451 is his speciality. 9.69 @139mph. Specializing in MOPARs- street to strip.
Contact Tim at BOWMAN PERFORMANCE in Export PA
724.325.4352
bowmanperf@yahoo.com

Good Luck and I hope your daughter blows the doors off that Chevy!

Set of CNC ported 440source stealth heads, 11:1 compression, MP.557 solid cam, edelbrock victor intake, converter that flashes to at least 4500 and you will rev that sucker to near 7000rpm.

If you're dead set on running stock heads, that will be your biggest bottleneck. Stock mopar heads just don't flow and the cost of getting them ported will quickly equal the price of a set of aftermarket heads. But if iron heads is what it's going to be, I'd be getting some work done on them by Dwayne (moparts member fast68plymouth) of Porter Racing Heads. He's a straight up guy and would be my first stop when working with iron heads.

MP max wedge heads maybe. Iron and period correct. Since you are not going stroker, you won't need much $ for the rest of the build. Not sure if it would really be any benefit over the stock port window. closed chamber might help with the compression.

You could offset grind that 400 steel crank to 3.52 for an extra twenty cubes. Unlikely your GM buddy would be any the wiser.

First off, congrats to the OP for raising a daughter RIGHT!

I'd use a tunnel ram, especially in a truck where there's room in there. Unless your daughter has specifically agreed to 1X4bbl, she's leaving performance on the table (IMO). I don't know which TR intake will work with a MW head, but someone here will.

And a roller cam is going to make more power than flat tappet. There are a number of guys on this board who'd be more experienced than myself at picking a grind; I'd expect to use something similar to what a super stock big block would run if this were to be a 'no prisoners' thing.

With the budget putting a ceiling on this thing, the Herbert valvetrain stuff might be pretty good. I'm running their lifters (in a pickup truck, with a tunnel-rammed "B" engine, natch), and the few dozen hours of run time I have on 'em have been okay.

Hard to work names like T&D and Jesel into the $5000 engine.

Picking pistons for a buddy's low $$$ 440 recently, we went with KB forged, because they were lighter than anything else in our price range, and were attractively priced to boot!

If I were building this motor myself, I'd look into a 7.1" rod w/ chev journals. The longer rod will help make the head 'look' better. Less rod angularity means that the peak piston speed during the middle of the travel won't be quite as high. So, it is slightly more forgiving of ports that don't have a lot of size.

You can buy 'em w/ ARP2000 bolts from RPM under part no. LG3-7100H for a few bucks less than 440Source sells 'em w/ the 8740 bolts.

Plus, it frees up about .175" of crankpin diameter if a little offset grinding is desired.

-Bill

Another vote for the long rods and following the rules.

Block will need a minimum of bore and hone $200
383 steel crank fresh and ready to run could be had for $200
Re-worked 440 rods for $200
KB pistons are what $ now 3-400 ?
Rings, bearings, gaskets theres another $300
Balancing $200

So your going to have mabey $1500 in the short block.

That leaves $3500 for the top end, can max wedge top end be done for that much? Do you have a carb or is that another expense? If so you can build a heck of a 850+ CFM thermo-quad for $50 thease days. Unless someone knows a good deal sitting around on a set of max-wedges you will probably want a 915 head ported by dwayne or someone else and that is likely to cost around $1000-$1500 ready to go, $300 for a new intake like a victor? We could say $2000 for a period correct topend.

Then for a cam you will spend a couple hundred for a good roller cam, $500 for roller lifters $100 for pushrods. $300 for some good rockers. You could spend a grand on a good valve train.

Now you have $500 for headers, distributer/ignition, plug wires, windage tray...

Don't forget to find any spare weight you can chuck out easily, then go spank that ugly old chevy

Not positive, no, but I haven't run across any cast big block crankshafts with a pilot bushing hole. I've gone through about 10-15 of them at the shop, just looking for good ones to regrind for stockish rebuilds and couldn't find one. But, being chrysler, it wouldn't surprise me one bit if they did a couple one off things.

A forged 383 crank has all the same demensions as the 400 cast crank.

The long rods are going to be a big asset because of the rules requireing period correct heads and budget wise a max wedge is out of the question. The reason is the only BB heads back then were very crappy and even the best were barely better than a 340 X head, a longer rod has proven time and time again to make more power at higher RPM when the head is limited and even the best 915-906-452-516 is not going to be a great performance head even on a 400, unless you have a long rod to keep it breathing. If she could even use a ported eddy RPM head or better yet a max-wedge style Victor the long rods would be much less of an issue but me I would still use them to make the motor last longer and lighten up the pistons, thats also why I would find a good light weight aftermarket I beam 440 rod to put in it if budget permitted.

A BIG Roller cam some good rods and pistons, and then rev the snot out of it. With the short stroke and hi rev nothing should touch it.