i have flowtech shorty headers for my small block. The headers are cheap and i do understand why they are not top quality, but its all my budget could swing. :pain: The o-ring port seals however were not even square with the flange, therefore would leak. I got my 90 degree die grinder out and thinned the "o-rings" down, but still left some meat on them due to the fact that is where the tubing is welded at. i have not currently fired the motor yet i am still in the process of rebuilding the carb and trying to sh** 200 bucks for a radiator. i currently have the gaskets provided with the headers on it but i am sure that something will occur and i will have to pull the headers back loose. If i don't have to and they don't leak, then why fix something that isn't broke, but if i have to pull them i have heard some guys using the stock manifold gaskets, since there aluminum and fairly soft. would this be a decent idea to try? also has anyone ever had to do this to the o-ring seals on there headers, and if you have how well did it go?
11-02-2011 05:51 AM
I have used the stock-type gaskets on several occasions and had no problem w/them- they actually work quite well. You might want to be sure the gaskets don't cover any of the header ports because they won't burn away if they do- they'll stay in the way. Trim as needed. Be sure to retighten the header bolts starting in the middle and working outward. Do this each time you run the engine until they take a set. If the gaskets aren't already cut, remove the bottoms from the bolt holes (see photo) so you can start the header bolts, then drop the gaskets into place- this makes it much easier.
I tried every gasket I could find on my block huggers. The only thing that holds up is copper. I took a 1/2 in thick piece of cold rolled steel and contact cemented sandpaper on it to start the header flattening exercise. At first I just scratched the high spots and used a large flat file to dress them. Gradually more and more of the surfaces became square. I also took the die grinder as you did and narrowed the "o-ring" on the ports of the headers. This pretty well cured the problem. You have to retighten the bolts a few times to set the gasket but once done they seem to stay tight. I replace the gaskets in the winter each year. You can anneal them but why mess with them as much trouble as they can be???