This afternoon i stopped by a local body shop where some guy had two old thrid gen bodies for parts on his project car. I asked him if i could look around the cars for parts i may need to rebuild mine this winter. I noticed one of them seemed to have quite a nice engine setup during it's time. The guy told me it was a 400 small block. The engine looks roughed up, the carb destroyed, standard manifolds (god knows why with a 400CI.) Apparently it's a very strong engine, sucks a bit of oil and he admitted it needed work.

He offered to sell it to me for 200$ Now, my 350ci produced 411hp before this summer but after my carb decided to act up and my engine started to burn oil, i notcied quite a drop. My current engine is showing age and will need to be rebuilt within the next 2-3 years.

So, if i'm going to invest in rebuilding a small block, would it not make more sense to take the 400ci for 200$ and rebuilt it rather my 350? I never really rebuilt an engine so i have no clue if one would be a hell of a lot mroe expensive or not.

 

Nah, if you're motor is tired and worn out, might as well start searching for the next one now. That 400 would be a good piece to rebuild. Shouldn't be very much more than a 350, everything related to an SBC applies really.
$200 isn't bad IMHO.

 

I would recommend that you pull off a head and check the piston size to see if that engine has already been rebuilt (scrape the carbon off and look for numbers on top of the pistons, or use a GOOD caliper to measure the bore). I would work out a deal with him to make the sale contingent upon if the 400 can be rebuilt.

 

Cool, i'll crack her open and check to see if the engine had some work previously done on it. So in your opinions, if that engine has never been rebuilt or bored to hell, go for it? I'd find it worth it if i can get a decent power gain out of it for a decent price. And here's another question to help me make my decision... if so many people are looking for power on their engines, why are 350's, 355's and 383's so common while i hardly ever see or hear about any 400's?

 

One thing I was always told was that the 400's had siamesed water jackets and that they were prone to overheating. Other than that I don't know. I've seen alot of them in race cars, so I don't know 100% about the overheating problem.

 

If it's "worn out" and "needs a bit of work" and "sucks a bit of oil" according to the seller, that probably means something more like "when I drove down the street people though it was the mosquito truck" or something close.

You can tell right away if it's a 400, by the block casting #. 509, 511, or 817. Anything else, it's not a 400. No "rare" casting numbers, "almost like a 400", etc. Either it is or it isn't.

400s came in regular factory cars and trucks, with exhaust manifolds and 2-barrel carbs. They don't "look" impressive in any way, as they come. I wouldn't worry too much about that. If you don't want the manifolds, have him keep them and see if he'll knock a few $$$ off the price. (hey, it's always worth a try, eh??)

Same for the carb and whatever else. Heads especially. Factory heads on 400s are among the worst of the worst, and aren't worth the gasoline it takes to haul them off, as far as I'm concerned. I've paid people to come get a pile of such things off of my property, since I'm too lazy to load em up and drive em to the scrapyard myself. If they're 882 or 624 casting, very common on 400s, leave em behind.

Make sure the block is currently NO MORE THAN .030" over. (4.155") If it's larger than that, the odds of being able to re-use it are slim because it's used up. 400s usually won't go as big as .060" over without problems, and often won't go .040" over.

There is no "overheating problem" with them. Only people who either don't know how to build cooling systems, or who have an unrealistic opinion of what "overheating" is. Keep in mind, a 70-30 mixture of water and antifreeze under 16 psi of pressure (a typical radiator cap) has a boiling point of around 265°.

The reason you don't hear much about 400s is because there aren't many of them left laying around in the world; and the people who have them are doing things with them besides talking about them. Guess how I might know that.

 

Perfect, you just answer about 110% of my questions. So, i'll rip a head off, make sure the block isn't bored over 0.3, if it isn't i'll take it, leave the garbage behind (manifold, carburetor, wires, starter, ignition) . check to see if the heads are casted 882 or 624 and if they turn out to be i can look for some aluminum heads or something.

Then for the real task. Buy a stand, find a place to keep that engine and figuring out a way to properly bring it there.