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BB Headers

1K views 5 replies 4 participants last post by  68WASAGOODYEAR 
#1 ·
Hi, I pulled out my sb and dropped in my 396 and I'm having trouble getting the drivers side header in, hard to clear the steering box. I tried a 2" and a 1.75" O.D header. the 1.75" headers are really close, if I raise the engine it may work? The engine sits a slightly lower at the rear, could this be the issue? I kept the same engine frame brackets and put new engine mounts, sb short and wide?? I tried the energy suspenion tall and narrow but they wouldn't slide over the mount brackets. Thanks.
 
#2 ·
Let me talk about the difference in the frame engine stands:

I kept the same engine frame brackets and put new engine mounts, sb short and wide?? I tried the energy suspenion tall and narrow but they wouldn't slide over the mount brackets.
What you describe as not being able to slide over the mount brackets is the difference between the short and wide and the tall and narrow motor mount. Because of the first ever factory safety recall; Chevrolet had to redesign the motor mount that the 327 and later 350 engines were pulling apart. Instead of just gluing the steel to the rubber mount in the vulcanizing process an actuall inter lock was used that made the mount taller than the simply glued together mount. GM changed the size of the frame stand to prevent car owners from replacing the interlocking motor mount with the cheaper vulcanized mount.

All engines that Chevrolet made that were factory rated above 300 horse came from the factory with interlocking motor mounts (includes all BBC and the hotter 327 and 350 engines). So it wasn't like the idea of a broken motor mount was unknown to GM.

As to header fitment. Look to the application page for the header you are installing. Note that the header will most likely "fit" every Chevy made except the Corvette and a light truck/van. So the fit isn't particularly good in any of the vehicles the manufacture says it will fit. They do this quite intentionally to reduce their inventory. If you looked at a Hooker header catalog of 1970 and compared it with today's offering you would see a difference in the number of part numbers listing applications. They were unique in the seventies when they were made by hand to fit your car compared to today's One Size Doesn't Fit All.

If you want a custom fit you have to buy a custom made header, just like everyone did back in the seventies before corporations got involved instead of muffler shop owners. Or buy a header kit and weld it up yourself.

Big Dave
 
#4 ·
Re: 1968 Impala bb headers

Thanks Dave, I have the short and wide mounts installed. I ordered the Energy Suspension mounts tall/narrow thinking that they would raise the engine position then giving more space between the engine and steering box allowing the header to clear and fit. The mounts wouldn't slide over the frame mount brackets. I owned 2 other 1968 Impalas, both ss427s and I installed aftermarket headers on both with no problems.
 
#6 ·
I have a '68 as well with a 496 BBC and had some real headaches with header fitment, especially with the raised exhaust port heads. I tried Sanderson block huggers and they fit perfectly. The passenger side dropped right in and I had to install the driver side from under the car, but it has clearance to the steering gear. Give them a look.
 
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