92Efi4.9

My exhaust is need of repair it leaks at 3# & 4# cylinders at manifolds. Air pipe broke of cat while towing a boat pretty sure both are being clogged up.

I hear good and bad things about headers but I've heard of a HD manifold. will a hd manifold fit on a efi?

justintendo

the manifold will fit but there is nothing to gain over the efi manifolds, as far as flow. single 2.5 inch outlet instead of dual 2 inch outlet..
just get some new efi manifolds.
the manifolds are not the restriction in a 4.9...

92Efi4.9

The reason I asked is because, Walker has a y pipe but it's on back order for a month. And it's kind of hard to find a di/so catalytic converter that's worth anything. I can find single high flow cats with air tube all-day long which means cheaper, less maintenance and option for turbo in the future.

justintendo

there are lots of performance cats available in almost any configuration if you look enough. building a 4.9, you have to scour..
several report the catco 9513 is a nice dual in single out unit that pairs nicely with the efi manifolds.

if you really are going to turbo it i guess you will need to use a something like the hd manifold and weld some cast iron.