Inliners International Forums General Discussion Hi Performance Offy 5416/Flowmast header incompatible

I started mocking up the intake, and exhaust to see about fabricating a power steering pump bracket with clearance. I discovered that the header flange that connects the tubes underneath the intake runners isn't allowing the intake to line up. Looks like I need to grind them down about 1/8 to 3/16 to make room. Then there's the issue that the two long clamps need to be replaced with two short ones. Are they still available from GM? I guess I could just use a short piece of 3/8 stock with a hole drilled through?

OMG getting more frustrated. I bolted up the intake. Then I ground about 1/8in of the tie between exhaust tube 5 & 6 which then fit perfectly, so I clamped it in place. The problem arose when I tried to dry fit the front half exhaust header(1,2,3). It doesn't fit under the intake. I suppose I'll need to support the offending tubes, and flatten them. Has anyone else ran into this?

Hi HeavyTruck . . . bolt-on isn't always just bolting stuff on. Having to tweak aftermarket stuff isn't unusual. Some headers do come pre-dimpled for clearance:


What is the finish on the flowmaster headers?

regards,
stock49

Thanks. It's not so much that I mind improvising, I just can't afford too many mistakes. That's why I rely on asking all of you here that have much more experience.

Well have you made any tweaks on the headers yet? If not maybe you should try to locate some pre-dimpled ones. If the headers are powder coated the finish will not hold up to a ball peen hammer . . . :-(

I like to mount them to the head and use a 1 inch diameter pipe placed on the header in the offending location. Strike the pipe to create the dimples required to clear. Do it in steps.

They only have a flat painted surface. I have already ground the connecting strap between number 5&6 down some to get it to clear the rear intake runner.

Thank you for the advise