rideocc

I have searched the forums for a reason why everyone says the 3.0 will bake the engine compartment when installing headers? I had a number of chevs growing up and put headers and exhaust on them with no problems. So is there a reason that this particular engine heats up the engine bay and the headers so much more that it is causing speedo cables, wiring, passenger side floor boards, speaker wires to fry? Is it just a clearance issue or is the engine that much hotter?

CoedNaked

I personally think it has something to do with clearance, but the clearance issue also depends on the brand/design of the headers.

Like many say the Downey products, while supposedly descent quality, run a little close to the firewall/floor boards/starter and in some cases due to the increased surface are of the headers, compared to the stock manifold, can cause more heat in those areas. But the NWOR headers are routed slightly differently and aren't as bad (or so I've heard/read).

As far as wires, etc being cooked/melted, I think that you can do a lot to mitigate for that issue by moving them away from the headers and/or insulating/protecting them somehow with the appropriate insulation wrap or tape or shield.

Also consider, related to clearances, that it is a fairly tight engine bay as well.

But if done right, many who have done the headers with a good exhaust system to compliment it, have nothing but favourable reports.

Unless you are a glutton for punishment, I would consider looking into having a reputable shop do the work. Yeah it might cost you some $$$ to do, but if you get a quote, and if they honour their work, and you are very specific with your instructions about things and put everything in writing, any issues that come about as a result of cooked things, might be covered to some respect, or at least the work will be done professionally by people who have the right equipment and know a thing or two about insulating and protecting various wires and such.

Schralper

Yes, everything is jammed in to way less space than a chevy.
There's not a lotta air flow thru the engine compartment.
The floor board issue can be solved w/ some dynamat inside on floor.
I was gonna put headers on my 3.slo until I saw NW Offroad wants like $600.
I mean their nice and all but I don't see the big benefit of headers for the HP increase on a 3.slo, I mean you'll never make the $ back if you sell the truck.

benwahballs

I installed the Downey *ceramic* headers on my 89 3.0L and love them. have had them on for a little over 2 months now, with one 1200 km trip under its belt. No problems yet, tightened the bolts down the other day, seemed pretty tight.

I agree with coed in the assumption that most problems are installation related, ie not spending enough time rerouting anything close. I probably spent 4-5 hours wrapping and re-wiring wires, bending lines, and I even made a sheet-metal cover for my starter that sits inbetween starter and header.

I also have 3" body lift which helps, im sure.