Urgent: Need Advice On 454BBC Headers For My 71

[71Nova454]

Hey Folks,

New guy to the forum here. I'm posting this for my dad. He just bought a 71 Nova with a 1970 454 Big Block Chevy motor in it. The car needs new headers and he's not sure what size tube to go with as well as brand/model.

He's not sure what headers are on it and isn't sure what the previous owner installed.

The 454 has been bored over something like 50thou and is a streetable motor running at 9.5:1 compression. It has a 750 Holly with a mild cam. The car is running true dual exhaust through Flowmaster Mufflers. A local mechanic that does a lot of work on high performance engines told him the car was probably putting out an estimated 450-470HP.

The car has a 4 speed transmission with a 3.73 rear-end.

The car also has power steering.

There's not much room to work with. He said the headers that are on there now only clear the power steering box by about 1/4".

He's wanting to get some reasonably priced headers that won't affect the power he's getting from the motor and the overall performance of the car.

So knowing all of that he asked me to find out...

1. What size header tubes would you recommend?

2. What's the best choice for Max. HP considering the clearance issue.

3. What brand/model would you recommend?

I guess the mechanic my dad took the car to said he's had some problems installing Hooker Headers in some of his rigs. Reading some of the posts in this forum, I see that a lot of people seem to have problems getting the right fit.

My dad's wanting an easy install and doesn't want to sacrifice any power. That's not too much to ask right?

He's been reading that perhaps sticking with the smaller 1 3/4" tube size might be better than the 2"+ sizes....Any feedback on that also?

Hope to get some responses from ya'll...The sooner the better...The car has an exhaust leak now that you can smell pretty bad while driving the car so he's looking to get the new headers installed ASAP.

Thanks for you time,

Michael
For My Dad, Terry

[Blue Bowtie]

What heads are on the Mk-IV? Some of them varied in exhaust port configuration, so header selection may depends upon the design.

[bobss396]

I'm anti-headers for street cars for a lot of reasons and personal experience. I personally would look into a set of hi-perf 396 or 427 Vette cast iron manifolds. Headers may actually cause you to lose power on the street, unless they have been tuned (adjustable collectors) for that car.

There was a guy named Brezninski in Michigan that specialized in modifying stock manifolds, both intake and exhaust, for stock car racing where you HAD to use stock components. He used to advertise in Stock Car Racing magazine and his prices were pretty fair.

Just my 2¢

Bob