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What is needed to make the 400 a good engine? I already have a 4-core radiator.
[/ QUOTE ]Nothing at all! It is already a great engine. It is just slightly different than ALL the other small blocks and some people don't understand them, remember, when people don't understand something it usually gets a bad rep. easily. They need a 4 core radiator because of the siemease cylinders and can't get away with a 2 core like every other SBC. The heads are different and don't swap with anything unlike every other SBC. When people try and use other SBC parts like heads on a 400 the results are disasterous and the bad part is when something gets a bad reputation, it usually can never shake it's rep. I love my 406, there is a HUGE difference in power from it and my old stock 350. The great part with a 400 is that they make low end torque like a big block but can still wind up just like a small block. I guess they are a little slower winding up than a 350 but mine sees 5500 RPM's all the time without a problem and can wind up faster than my old 350 IIRC. My blazer with 35's and 4.10's will out pull my '76 C30 with a 454, 31's and 4.10's.
I think the stock numbers are 205/335 on the 454 and my 406 is about 315/400. /forums/images/graemlins/thinking.gif If you plan on building it up for some power don't make the same mistake I did which was to spend money porting the stock heads. Just buy a set of Merlin torquers or Pro top lines, any aftermarket head designed for performance is going to vastly out flow the stock 400 heads. Just make sure you order them for a 400 with steam holes. /forums/images/graemlins/wink.gif It is vastly important to go with a bigger head on a 400 because of their size. The stock heads work great on a 305 but that same size head on a 400 doesn't cut it. Stay away from a lot of compression, 400's don't like high compression because of the heat generated from the seimease cylinders.
If yours is a complete original 400 than tear it down and do your standard SBC rebuild with bearings machining, and gaskets. Keep the 400 rods, they are different than other SBC rods. Go .030 boring to make it a 406, no bigger or you will have overheating problems.
