One thing I have learned over the years. When you want to do a performance engine build, it will always cost WAY MORE than you think it will. If you think it will cost $7000, it will end up costing at least 10k. If you think 10k will do it, it will end up around 12-14k. Its just the nature of things. Alot of that is the cascade effect. Where once you get the engine out and off to the builder, you decide, hey, I might as well do this, or upgrade this while the engine is out. So making a good plan before you start is always a good thing. Price many different options. Add a minimum of 25% to whatever you think it will cost, and have that money budgeted and ready to spend if you need to. Theres nothing worse than a half built project sitting in the garage for 3 or 4 years because you didnt do your homework and were 50% off with your cost estimate.
Also, never forget about the most annoying thing of all, THE UNEXPECTED! This one will bit you in the ass no matter how hard you try to avoid it. So always remember this one thing, SHIT HAPPENS! and it happens alot more frequently in High Performance Builds. I have friends who laid out 15k for an engine from Engine Factory, only to have it blow up within the first 100 miles. Then Engine Factory, being a bunch of low life douche bags, did not do anything to help him. Then he went to another builder, spent another 5k fixing it, only to have more problems, causing him to pull the engine again because the fasteners they used on the rockers were shit and 2 broke, sending debris and a push rod southward. He finally got fed up with the whole project and called Proformance and got them to build him a Dart Block 427 using his AFR heads from the engine factory build. That thing is a total BEAST now. But even that engine came with one big surprise. The distributor was new from MSD and installed by Proformance. Something was wrong with the Distributor gear and it turned to metal shavings in the first 10 miles. After a call to proformance and dropping in a new MSD Distributor with the Proper gear, its been doing great. Total Engine money budget was 16k, total actually spent was almost 30k.
This is a prime example of SHIT HAPPENS. Nothing he did wrong, One bad engine builder, 2 poor vendors, and one manufacturing defect made him spend twice as much as he anticipated.
Also this is a great article on the distributor gear subject.
http://www.stangtv.com/tech-stories/...t-the-details/
This doesnt even consider what the ramifications of all that extra power will do to the rest of the vehicle. A unibody car will Twist with enough rotational force. Also, the transmission will explode with too much power and torque going to it. So will the rear end. Its all a system. A motor with big power will find the weakest link one at a time until there are none. So keep that in mind. Extra bracing may be required, upgraded transmission may be required, and rear end upgrades and gearing will very likely be required. Dont forget BRAKES! Brakes will need upgrading. I would go with 6 piston Wilwoods.
From all of the people I know, I can give you 2 companies I would trust to build for me.
http://fordstrokers.com/fordstrokers-long-blocks/dart-351-long-blocks/dart-408-427-Longblock
http://proformanceunlimited.com/