400 BB build questions

After a lot of looking around in my area which I have dubbed "Ford and Chevyland" I have managed not only to find a decent 383 but a buildable 400. I have decided to build the 400 seeing as how that is what my '72 Runner had in originally, however I am wanting my baby to have some get up and go. I am ideally wanting in the neighborhood of 350 to 400 hp out of my 400 and could use some advice on how to go about it.

Here is my idea and would appreciate feedback\suggestions.

8.75 rear with original 3.23 Sure grip rear end
Aluminum Radiator with electric fans (to free up some horse power that the original fan setup might rob)
Electric water pump (same reason as above)
Dual Plane intake
Thinking a 750 cfm Edelbrock carb with electric choke
A camshaft in the neighborhood of 268/280 grind
727 Torqueflite auto trans built to take 400hp (not sure on brand yet)
March Serpentine Pulley System
Car will have A\C. ( Dark Green exterior and interior+ hot/humid Ar weather means a bad time without it )
Head Casting numbers 452 intake 2.08 exhaust 1.74
Power steering.
Standard Electronic Ignition distributor


That's about all I can think of so far. If anyone has a way of putting together these ingredients and calculating a ballpark on H.P. or suggestions, please let me know.

I look forward to hearing from everyone.

you going to just leave the heads stock?

thinking so for now. That is if my goal is achievable with the heads stock.

mopardog said:

thinking so for now. That is if my goal is achievable with the heads stock.

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i don't see 400 h.p. in the cards with that mild build.

any idea what I'm looking at as build sits now?

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Would it even be possible to put the 383 crank in the 400? If so would it help any with some aftermarket pistons? This is my first big block build so a lot of new territory here for me.

depends on the c/r of the engine. stock 400 4 bbl put out a little over 200 h.p.

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mopardog said:

any idea what I'm looking at as build sits now?

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Would it even be possible to put the 383 crank in the 400? If so would it help any with some aftermarket pistons? This is my first big block build so a lot of new territory here for me.

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check out this 400 build, if you got the money:
http://www.hotrod.com/how-to/engine/ccrp-1207-chrysler-b-series-400-hemi-power-at-half-the-cost/

any ideas?

do you have a set budget?

not counting serpentine set up and radiator set up.....looking at about 1200 to play with

Shop for new pistons and a set of headers to get 10.5 compression and you may be able to reach your goal at the crank. May need to budget 600-700 dollars for custom pistons.

Recommend installing a 440 forged crank or better known as a stroker motor. I build two engines. Set up for 10:1 resulting in lots of torque and HP. Exhaust headers at 2.5 or 3" with X pipe to the tail.

400hp is totally achievable. You can do it with only a few modifications to your current plan. Strokers are good, but not necessary to reach your power goals. My suggestions:

Forget electric water pump. These are really not intended for the street. You can also save some money by staying with factory fan setup. Electric fans will free up hp, but at your build level, I think the money would be better off spent on something else. Hell, I have a factory 7-blade thermostatic fan on my engine making over 500hp. Likewise I would ditch the serpentine setup. I see the benefits of a serpentine belt, but at your level, I would spend the two grand on something else unless you just HAVE to have the bling. I run v-belts on mine, though I may upgrade in the future to the Eddie Motorsports true serpentine setup.

Enough for what you shouldn't do...

Your plan for ignition, carb and intake is good. Performer RPM is an outstanding dual-plane intake.

The MOST IMPORTANT things are to increase the compression ratio to 9.5 or 10:1, and use that money you saved above to buy a set of good quality aluminum heads. The corresponding Performer RPM heads are a suggestion. In fact, you could just go with the Edelbrock Performer RPM top end kit for a 383 (p/n 2086). They say they made 421hp with their kit (on top of a decent short block, of course). You might make a little more by virtue of your bigger cubes and better airflow in the large 400 cylinder bores. Cam specs are 238/246 @.050. Very streetable. I know people might have varying opinions of Edelbrock products, but I have always had good luck with their components. I just recommended them here because they were the first to come to mind and they offer most of the components you need without having to mix and match parts from different companies.

A big-block Torqueflite will not have any problem handling 400hp. TCI Streetfighter is a good quality low-buck choice.

Good luck!

Thanks for all the great advice. I know now I at least have some options!

I just put a 400 together. Here is what we used.

383 steel crank and rods
Keith Black kb240 pistons
Zero decked the block
440 source heads
Comp XE-274-H
Eddy RPM intake.

We ended up with 9.4-1 c/r. The 440 source heads cc at around 82 or we would have had a little more. 915 or 516 heads would get it higher as well. The kb240 piston does bring the piston to about .020 below the deck which is a lot less than the stock type piston. I believe they were about .125 below the deck. Have fun and good luck with the build!

I would at least do a pocket port job on the heads. Those are really bad as they left the factory and isn't that expensive to do and well worth the money. Do that and at least make sure the ports match the intake.

You are all probably tired of it but here it is again............

http://www.forbbodiesonly.com/moparforum/showthread.php?80843-The-slug-400-on-the-dyno&highlight=400+2bbl

Homstead makes a great point about the importance of deck height. This is pretty much what I meant by good quality short block. Factory compression is way low in the smog-era 400 engines and paying close attention to deck height and cylinder head cc's is the route to good compression. I have ported 440 source heads on my engine and I like them. Cylinder head material is mostly unimportant (iron vs. aluminum), the key is good flow, as Cranky pointed out.

IQ52 said:

You are all probably tired of it but here it is again............

http://www.forbbodiesonly.com/moparforum/showthread.php?80843-The-slug-400-on-the-dyno&highlight=400+2bbl

Click to expand...

Never get tired of your data! Having the right instruments to benchmark takes all ambiguity out and the numbers tell the story. Big blocks always have potential, first step is to uncork and let her flow.