Just touching on exhaust and breather a little
I agree with most everything said though not a Chevy man I do have a couple comments on exhaust that for ME made a difference. Please listen to Tech I've learned the hard way.The X pipe is superior to H pipe in my opinion . Long tube headers are great but in my71 Lincoln Mark iii,1976 Cordoba and 69 Ford LTD/Cobra they ALL dragged terribly. over every bump or incline. The shortys aren't as good as long tube headers nobody is debating that but they are better than manifolds to ME and MY CARS. Also I had my exhaust going all the way out the back l6ft out back that is. It was loud if you were out back but inside or on the side of car not the best. So I dumped two of them out the sides in front of rear tires and used side pipes on another. The underneath may not be good idea. I had my exhaust dumped right in back of front tires on my Lincoln and that did get on my nerves real quick. Just my opinion based on my experiences that's all.The breather to me is almost meaningless. I've run every kind of breather known to man on dyno means little to nothing. Proof of that. is when I went to a functional hoodscoop on my 1969 Ford I see no difference whats so ever.
I wouldn't get to caught up in the 4 bolt main debate. That ain't that big a deal anyway
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