[steve_oo]

I have been reading everything which I can find on this board about exhaust manifolds and headers for Broncos... but still have a couple questions...

I just bought this truck 3 days ago, while going over the truck I have noticed a cracked exhaust manifold on the passenger, side which explains the exhaust sounding leak which it had when purchased..and the "rumble in the exhaust on deceleration" which I am assuming is backfiring in the exhaust due to cold air being sucked in the cracked manifold.

there is no carbon foulding around the crack on the exhaust manifold, at least on the visible area of the manifold... do these manifolds have a tendency to crack and not leak? as I have read somewhere else that another possible area of leakage is the EGR tube on the back of the motor, which I will check out tomorrow more clearly....

Given that there is a crack in the passenger side manifold I am assuming I need to replace as I had said when I back out of the motor it is definately sucking back in and causing some type of detonation..you can hear it through the exhaust.

Driver side manifold seems to be fine, should I just replace the passenger manifold with one of these replacements? http://broncograveyard.com/bronco/i-30005_exhaust_manifold__302_right_w__o2_hole.htmhas anyone on the board used one?

or should I just get a set of hedman headers and replace both manifolds while I am at this? the only thing which I am hesitant about is breaking bolts in the head, I have not dealt with that before.... I have been soaking the bolts everyday in PB Buster in anticipation of this repair...

also if you suggest headers, do you suggest painted or ceramic coated? I know ceramic coated retain heat better/wont rust, etc however I only need these guys to last a couple years until its time for a motor overhaul...
Please let me know what you guys think and I appreciate the help!!

 

[psygn0sis]

Same thing happend to my 66' stang with a 351w. The crack got bigger and bigger untill it was a gapping hole !!
I just got a set of headman headders for it.. they are cheap... only about $150 or so bucks.

My 2 cents would be to go for the headers.. fix the problem and never worry about it again.. and gain a few extra horsies while your at it.

Now about the bolts... the soaking in PB is a very good idea... I never stripped or broke a single bolt on my 351 when I did it... just go slow.. as the bolt is comming out give a few good squrts to make sure the whole bolt is wet.


BTW: are you gonna go full length or shortys ?

 

[mda]

I found Hedman headers on my 92 to have very poor port alignment and they would have required significant notching of the frame on the passender side.

Hooker supercomps (Full Length) fit much better. No problems since 2001.

 

[steve_oo]

BTW: are you gonna go full length or shortys ?

I should have been more clear, I am going to go with shortys so that I don't have to mess with the $400 exhaust that was just put on the truck... there is nothing wrong with it and additionally I don't want to mess with the fit of full length headers..

 

[bronco1]

It sounds like the leak is a broken check valve behind the upper intake manifold,to check for this,start the engine and then listen for where the noise is coming from,you may have to get some one to rev the engine in gear a little to get it to make a noise(park in an open area so that if the Bronco jumps ahead a little,you are not in danger of getting hurt or crushed)You can also use a piece of heater or garden hose to your ear and move the other end around to various areas to locate the exact place of the leak.

 

[raisin]

I replaced both sides for $50 a side from A1Auto on Ebay. Been good for 2 years....