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I have a '72 small block with the Paragon side pipe covers and Mike's Stainless pipes bolted to the stock exhaust manifolds. I am looking for headers that will allow the exhaust pipes to mount in the same position as the stock manifolds. I don't want to modify the new pipes unless there is no other alternative.
i would think a pair of shorty headers would provide the closet fit to a stock exhaust manifold.
i may be very wrong though..really expensive too, and not even equal length tubes.
The performance increase is zero with the shorty headers. Unless you have another reason, the cast iron manifolds are just as good and the price is right especially if you already have them. Either that or go to the long tubes and weld it up. Those side pipes are pretty restrictive anyway so not sure it will make that much difference.
Throwing out another option and acknowledging that the side pipe set up is not the ultimate performance answer. That being said, my car is a 69 convertible with factory side pipes and I desired a bit more performance but am not chasing a 11 second ET. Below was my solution/compromise; appears that Qwank and I were thinking in the same space. Unfortunately, I don't believe this will work with your existing pipes.
1. Hedman side pipe headers listed by Boswell, Barry's 70LT1 & Qwank.
2. 2.5" straight pipe, mandrel bends and turndowns to make my own exhaust
3. Borla XR-1 Bullet Mufflers - mounted as far to the rear of system as possible. https://www.borla.com/products/xr1_b...rt__40641.html
4. Spacers between the body and side pipe covers
I have nothing to add but a question. Has anyone tried fitting a 3" pipe under the stock covers?
That's on my "to do" list for this summer. As Stingr69 said, the side exhaust mufflers are quite restrictive. When I did some 1/4 mi years ago, thru the mufflers vs open headers was about .5 second.
The goal is to try a glass pack as mentioned,, which are 3.5", maybe make something using 3".
The borla mufflers in my previous link are 3.5" in diameter and needed spacers between the factory side pipe cover and body to have enough "cavity" to fit. The Borla mufflers are more of a resonator than a muffler and sound great, but I would not want to listen to the exhaust on the open road at 70 MPH for very long (loud pipes save lives). Unable to speak to the performance of current generation glass packs but on my low 12 second L78 Chevelle SS, they were not the answer. In a situation similar to yours, opening the exhaust gained ET; in the early 90's.....12.teens at 113 MPH with a 2.0 sixty foot. Was never able to lower the 60' with the 4-speed and 3:55 gears but it was/is a lot of fun. I struggled with a solution/compromise on the side pipes and have no way to prove if my system is good or bad; the car is a driver not a racer. That being said, my gut says, glass packs are not the answer but I don't have a solution to offer......building/testing/learning is the fun. Best of luck - Don
The performance increase is zero with the shorty headers. Unless you have another reason, the cast iron manifolds are just as good and the price is right especially if you already have them. Either that or go to the long tubes and weld it up. Those side pipes are pretty restrictive anyway so not sure it will make that much difference.
I appreciate your feedback. The reason I started looking at headers is the engine in the car was stroked to 383 by the previous owner. Heads, cam, intake have all been changed. The thought process was that headers would allow the engine to breathe better. If this is not the case, then there is very little reason for me to install them.
I appreciate your feedback. The reason I started looking at headers is the engine in the car was stroked to 383 by the previous owner. Heads, cam, intake have all been changed. The thought process was that headers would allow the engine to breathe better. If this is not the case, then there is very little reason for me to install them.
The situation you're facing, is that headers would indeed flow better, but that would just move the restriction a little further "downstream".....
05-01-2019, 04:15 PM
Headers for Factory Side Pipes
