DIY 4 Branch Manifold

[brainbug007]

I was wondering if anyone else had gone this route as from what I've seen so far these are quite expensive to buy off the shelf! I was hoping to be able to make one a bit cheaper so that my exhaust pipes come out of the engine at more of a right angle to enable me to place the engine a bit farther back as the downpipe at the moment is very close to the passenger footwell. Does anyone know of any good guides?