exhaust manifolds
 

does anybody make a narrower exhaust manifold or a tube header than gil manifolds?

not sure about the 454 but on my small block the gils are 1 " narrower at the bottom than the stainless marines i just fit ....but the gils taper out at the riser flange 1/2 " more than the Stainless marine

exhaust manifolds
 

i have gils on 454s. i am trying to get as much space as possible between the two inner exhaust manifolds. as they are they only had about a 1/4 inch them. i would like to run tall decks but cant if i cant get any more room between the manifolds.the boat is a 79 chris craft excaliber 32ft the hull is pretty narrow to begin with

IMCO Narrower?
 

Dear Excaliber,
I have worked with both the GIL and IMCO exhaust manifolds (quite a few as a matter of fact) and although I have never measured the width I am sure that the IMCO's are much narrower. Call Fred at IMCO and ask him to measure them for you.
Sincerely
Dennis Moore
Merc Master Tech

exhaust manifolds
 

thanks for the info i will give thom a call