Chuck84TA

So I understand that the ZZ4 heads have "D" shaped ports for the exhaust manifold. If I buy these headers for my stock 305 will they fit and work well with a future ZZ4?

If it works, will I loose some performance due to the "D" shaped design?

Thanks
Chuck

Fueled

I think if the 2055's are at least 1 5/8 you should be fine. It's not so much the D shape of the exhaust port as it is that they are raised 0.100". The ZZ4 heads are almost identical to the old 113 heads from the l98 vettes, which had the raised ports as well. Or, you could always go with something bigger if your main concern is performance.

Chuck84TA

So 1 3/4 would be best?

Is that too big a gap in the tube for a 305?

Fueled

1 3/4 should have no problem bolting to a 305, nor hurt performance in any way.

Chuck84TA

Thanks! ����