Just got my headers from dyno don, and I had a quick question about my Split Lock Header Bolts from Percy's. It says, "there must be a minimum of 1/2" of bolt threads in the head" but I can already tell that these are to short. So I just want to make sure that the 1" long bolts from Percy's wont be to long... right? They wont break through into a coolant passage or something like that will they?

The heads are Aluminum L98 Heads off a 90's vette.

 

I broke into the coolant passage with 1" header bolts on my World heads and 2055HKR's with Felpro gaskets.

You might want to measure the hole depth, or hand tighten the bolts into the holes w/o the headers or gaskets and see how much gap you have between the head and the bolt head. You may find you need to use a thicker gasket.

 

I ran into your problem recently also. I bought some Dougs LT's and the mounting flange is much thicker than the old shorties.I also have the really thick reusable type gaskets and my old bolts only went into the head with a couple of threads. I can live with it for now because the engine is still on a stand but I wouldn't drive it that way. Like the other post suggests definately measure first. It would suck to ruin a set of aluminum heads!

 

I posted over at the corvetteforum, and it looks like the 1" long bolts are what I need. Just to be safe though I'll measure the depth of each header bolt hole, when I remove the exhaust manifolds.

Thanks for the input and help.

 

Studs! never have that whole problem again, a dab of red rtv on the nut and they will stay tight forever.