Header clearance

[ONEBAD78TA]

Hey guys,I've got a78trans am with eibach 600 pound springs ,Viking shocks ,global west extended travel setup,and I was wondering how much clearance from the road and headers do most people go for ,,I'm thinking I'm only going to have about 2",,I'm probably going to have to chart my course to avoid any speed bumps LOL

[Gscherer78ta]

Originally Posted by ONEBAD78TA

Hey guys,I've got a78trans am with eibach 600 pound springs ,Viking shocks ,global west extended travel setup,and I was wondering how much clearance from the road and headers do most people go for ,,I'm thinking I'm only going to have about 2",,I'm probably going to have to chart my course to avoid any speed bumps LOL

The lowest point on my 78 TA with 800# front springs is 4.5" and I hit on speed bumps, and some driveways. A friend had 3.5" of clearance on their headers and switched after a month of driving because they were hitting frequently.

I would be surprised if you didn't scrap those headers frequently.

[Panteracer]

I have 2 1/4" Tweaked up the
Compression on my Vikings that have
450 lb springs. Hit quite a bit at the dip
auto crossing last weekend. Most of the time
Ok unless road is bad

Video shown on members videos. Thundercross
You can see the dip at the start

Bob

[mach1stang]

My boss sits right at 3" off the ground at the rockers (2.5 or less at the k-member), so there are lower spots here and there and I DD it with no real problems. Speed bumps are the least of my worries cuz you can normally take them at a angle and avoid scraping, but steep driveways are the big killer! My car has a big splitter so that doesn't help but I scrape pretty bad going up or down steep angles.

[IMPALA MAN]

Many times this is dictated by the floorboard and not the header. You need about 5/8" between the top of the header collector and the floorboard to compensate for engine torquing.
The collectors are usually 3.00". So simply put, where the collector is, measure from the floorboard to the ground. Say you have 5.00". Subtract 3.00" for the collector, another 5/8" for the clearance. This should total 3-5/8". 5.00" - 3-5/8" = 1- 3/8". If you want any more ground clearance.......you guessed it, raise the floorboard, or the car.
Now if you have more than 5/8" between the floorboard and the collector it could be a few different issues.
1. Incorrect transmission installation..transmission too low in the vehicle.
2. Incorrect engine installation. Engine too low in vehicle.
3. Headers designed to hang too low (why would any company do this) OR incorrect engine and or transmission location compared to what the headers were designed for.
Keep in mind there are many different engine mount combinations, trans crossmembers, etc. that can cause issues. Most of the time if you use what the product is designed around, everything will work. It's when you start mix matching is when problems start to appear.

Aside from everything, buy as much clearance as you can.
1. Use a band clamp or four bolt flange instead of a three bolt flange at the collector. The three bolt is a triangle meaning that the point of the triangle will point to the floorboard or ground. The four bolt allows better clearance due to you being able to have a flat on top and bottom.
Better yet, the band clamp gives you excellent clearance, especially when you turn the bolts to the side. Here is an example.
http://www.afcodynapro.com/DYNATECH/706163617

Hope this all helps and the best of luck with your project!