[mechanic17]

RE: exhaust. Have to disagree with 2ManyTAs. Log manifolds are a definite hindrance in the midrange+. I hate headers myself, and the RAREs with 2.5" outlets work well! Would love to have long-branches.

I once had a dual exhaust made/put on by a "reputable shop," and I specified 2.5" all the way and even provided the straight pipe. Later, upon inspection, they had used some pathetically restricted bends, especially toward the front of the car: maybe as small as 1 3/4". By the time I went back, they were out of business. So you might want to have a look at yours on a lift.

[rexs73gto]

tryconcom , all the Pontiac heads from 1967 were & are open chamber heads. The only heads that were closed chamber heads were the 670's in 1967 for the RA III engine. All the heads after that are open chamber heads. Unless you go back farther with some of the 389 heads. But again all 400 heads are open chamber heads.

[hada76]

Originally Posted by mechanic17

RE: exhaust. Have to disagree with 2ManyTAs. Log manifolds are a definite hindrance in the midrange+. I hate headers myself, and the RAREs with 2.5" outlets work well! Would love to have long-branches.

agree, logs are the worst, you will not get the full benefit of duals if you keep stock logs on