400 engine Help Needed

IQ52 said
You might consider using the new 75cc Edelbrock E-Street cylinder head. It is supposed to be out in about 6 weeks. Summit Racing is selling them for $979.95/pair. Order them now and get them at that price. Edelbrock's part number is 5090. Jeg's had them also the last time I looked.

I agree. I think the key is compression and closed chamber heads are the simplest way to that, plus a better port, lighter, and very close to within the budget when you combine them with a cam, intake, and gaskets.