First off, let me say that the 'new HAMB' rules! Second, I am building a '49 chevy pretty much from the ground up. I need lots fo stuff to get it rollin' as I bought it pretty much just as a body and frame. Anyway, I found a O/T '74 Malibu with 400 small block and auto ******. I don't really know a lot about the 400's, but I do know it probably has a ton of smog **** on it. I can get this thing cheap and it runs and drives pretty well. What do you guys think? Is this thing worth it to use the motor and ****** and anything else I can scavenge or should I keep looking. Oh, I can get it for like a grand. Help me decide! It's either this or I'm buyin a new welder.
If it's the 400 i'm thinking about,it a siamese cylinder block. No water jackets between the cylinders. They run really hot,and in 74 they had **** for horsepower. For $1000,it might be a good deal though. The rear ends are really wide in those Malibu's too. Might not fit. Big difference between a 72 and 74.
Better deals to be had out there. Im not sure about 400s myself, but for $1k you can grab some lowley half ton or 3/4 ton chevy truck on craigslist all day long for a few hundred. You know, the old reliable but rotted, headlights are falling out and facing each other, **** like that. Plus, most 3/4 ton 2wds had TH400s in em. Then at the end you can take what you need, part any good stuff and s**** back the rest for most of your purchase price.
Yeah, look for a pickup or van. I just scored a '93 Chev van with TBI 350, 4L60E, complete, runs GREAT for 800 bucks, and have EVERYTHING I need for my Diamond T pickup project. The van will be worth almost as much as s****, without the stuff I'm using, as I paid. People are giving these things away looking for economy. Lucky us.
SB 400s running really hot is not really true. Had one that had small chamber heads,cam and 750 Holly and ran 180-190 here in Phoenix in the summer {hells front door] Used a 65 Mustang V-8 rad and a 15 inch flex fan. Was in a T Roadster no hood though.
If your not overly **** about your historical correctness i'd say you can't do better then a 400 (as far as small blocks go), they are great motors, especialy stoked, yes they are siamese bored but that doesn't casue any heating problems, actuly makes 'em stonger and being out of a car it'll most likey make it a 2-bolt main that unlike other small blocks are actuly better then the 4-bolts. Or at least that's what i think?
Explain to me the siamese block deal. Also, why is a 2 bolt better in the 400 block? I think that these motors only made like 180hp. What can I do to get the power level up, on the cheap? T.
I'm not a small-block chevy guy ever, but I've read that they only have a rep for running hot because there's steam holes or different coolant p***ages than other belly****ons and people often ran heads built for other small-blocks without drilling the heads for them. That lead to overheating and the reputation. Like I said, I know jack **** about em, but look it up, because, if you are gonna run a small-block, it might as well be a big one...
The first two and last two cylinders each side the castings touch. On the block deck between these cylinders are a pair of 1/8 "steam holes" these need to be put in any head you use if they are not there. These provide some water flow in that area so you do not have a local hot spot.The reason for the low HP rating is 1 they have a 2 bbl carb and 2 that's when the car makers started using installed HP numbers rather than test stand with no accs. installed. The one I had I put some 1.94-1.6 67 CC heads on it and with a 350HP 350 cam and a Victor Jr. with 750 Holley. Made good power from idle and I regulary turned 6K + with a stock 2 bolt bottom. With a 3.55 rear and TH350 in a 1900 lb T Roadster it was damm quick. Ran it that way for 2 years untill I sold it with nada problems.
Cool, thanks for the info guys! Is there anything else different on the 400 block besides the "steam holes"?
They're balanced differently, so you need to use a 400 specific balancer and flywheel/flexplate. Also it's a rumor about them running hot.
A good donor car/truck is something that has the drive train that I want and still has left over parts that can be sold to bring down the cost of my drive train. I used a wrecked Camaro once, a rusty Suburban with new repo fenders and not too long ago a wrecked Monte Carlo. All had relatively low mileage well cared for drive trains. I sold the parts on the Camaro for more money than I paid for the car and kept all the drive train. I ended up having 500 bucks in a complete low mileage 4X4 drive train from the Suburban. Personally, I stay clear of the 400 engines mainly because I understand that I don't know enough to play with one and I don't like the learning curve anymore. You can pay more for a donor if you can reclaim some of your investment.
I love the 400 sbc, the best sbc there is in my opinion. They do not run any hotter than other sbc's if they're maintained properly. If the above mentioned steam holes clog from poor maintenance then you will have problems, but then you deserve it now don't you. I think one reason hot rodders think they run hot is that often guys pull out a 305 or something and drop in a 400 and try to use the same radiator. Yet the same guy wouldn't even think of doing that if it was a big block, even a smaller 396.
Yes 400's are externaly balanced, so you have to run the correct balancer and flywheel/flexplate (not a big deal), I believe they also have a bigger crank journal. Honestly i don't know why 2-bolts are supposivly better,It's just something i heard along the way. But i know most the race guys use 2-bolts blocks with splayed caps.
Is all the ancillary stuff other than the balancer and flexplate the same as other SBC blocks like intake, oil pan,manifolds, waterpump, etc... Is this block more expensive to rebuild than a 350? Thanks again for all the opinions so far.
I once read that the 2 bolt 400s are more desireable than 4 bolts because they are beafier around the main bearing webs and not as prone to cracks around the threads as the 4bolt ones. At least that´s what I remember, but I´m not too sure. Chris
The last running, driving 400 I bought was $600 at auction. This was a few years ago and it was a 4 door Caprice. I thought I paid too much for it back then. I think it could be a good donor for a small car, just do everything you can to cool it, including the taboo electric fan.
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