Hi Everyone,


I have been reading your post for a long time but have never
submitted one until now. I hope that somebody out there can help me.
I have a 68 ford Bronco, Brand new 302cid, 351 windsor heads (bigger
valves), Holley Truck avenger carb, and a brand new bronco c4. The
reason I have posted this message is because I have a problem I just
cant beat. I have exhaust fumes coming into the cab. This may sound
easy to correct at first, but I have already done all of the obvious.
I have replaced both of the mufflers, the pipes only have about 3000
miles on them, and for good mesure I have checked them anyway. I did
the donughts off of the manifolds which (did seem to help a little),
and I have put exhaust tips on just to make sure it is clearing the
back of the truck.
The exhaust system is 2" and it is straight back without a cross over
of any kind. And finally the manifolds are stock but not cracked or
broken in anyway, and have brand new gaskets and I have checked the
torque several times.
However the only time that I have any problem is when the window
is down. I have heard tidbits about a vortex being created by having
the window down, that sucks into the cab. I'm not sure this is true
but any help will be greatly appreciated. Anyone who has ever ridden
in an old Bronco knows that in the summer there is no way to not open
the window or take off the top in the summer. I am truely desperate
here. I am a competative athlete and cannot take the fumes. I'm
afraid that if I cant solve this problem I will have to get rid of my
old bronc, and thats too bad because with this engine set up she
screeams!

Thank you in advance for any help, I throw myself on the wisdom
of the group.