[mechanickeith]

That is one way to do it if you have a hedder made for the 4 cylinder. But, it should be equal length tubes. Pair the # 1 & 4 cylinders together & # 2 & 3 together. A much cheaper way is to get a used 3 tube hedder. You should have at least a 2 1/4" pipe all the way out the back. Find one that looks like the picture, right side 3 tube hedder. You will have to fabricate a block off plate for the bottom of the intake manifold where the exhaust crossover pipe is bolted.

You may want to retain the stock exhaust manifold. If you do, have a system installed from the manifold back, with a 2 1/4" pipe.