high flow catalytic converter

[mooseboy84]

I am looking for recommendations for a high flow cat (or maybe just a regular cat?)

I have a 69 longbed with dual straight pipes and glass packs, 2.5". I just cant take the smell of the exhaust when idling and driving around anymore and need a cat on there to cut it down. I dont think I am running too rich and actually bought a A/F guage I want to install at somepoint to fine tune carb, but will install it at a later date. I have a stock 350 crate engine (260 hp rated) so nothing fancy.

Can anyone recommend a set of cats I could install? Is there any benefit, or should I say, would "high flow" cats be better and rob less hp, or would a regular truck cat be ok?

Oh, and to make it all the worse, I am in California which already I know I cant order half of anything online dealing with exhaust.

Thanks

[cableguy0]

Get the carb and timing straight if it stinks that bad at idle. What kind of carb are you using? Hopefully not an Edelbrock.... Where is your timing set? What kind of ignition system are you using? Is your plug gap correct? Installing cats on something that stinks of fuel will only lead to melted cats. Where does the exhaust exit the truck?

[mooseboy84]

Thanks for the response.

I have static timing at 12 degrees with a generic HEI unit. Yes I have an edelbrock Everyone hates them, but it came with the truck. I believe its a 1406 model. I just rebuilt it and it works, but does need to be dialed in. I adjusted the idle with vacuum gauge so thats good to go. I do not believe it is running excessively rich at idle, it just has that partially unburnt hydrocarbon smell, not a flooded carb raw gas smell. It basically smells like a damn smog shop, lol. I was adjusting the carb this past weekend outside and the damn smell of it is what made me think about installing cats.

I am aware cats will burn up, especially if theyre running very rich. I purchased an AF ratio gauge that I need to have welded in, so I can fine tube the carb. I also have a couple small cracks in the exhaust I need to weld up LOL. The exhaust setup uses headers that connect to 2.5" dual exhaust long tubes with glass packs near the back. (Yea its loud) The exhaust exits under the rear bumper...its a longbed.

I was going to have exhaust cracks welded and bung installed and work on dialing in the carb, and after all that, was still looking at cats just to clean up the remainder.

[cableguy0]

You CANT tune that rich idle out of that edelbrock carb. First thing you need to do is get a fuel pressure regulator and set fuel pressure to 5psi. Even if you have a stock fuel pump its putting out too much pressure. The easiest fix would be to use a carb that is actually tuneable but we can help you with what you got. First you need to set your timing curve and add a little advance at idle. That will help too. The fuel pressure regulator is a must with the Edelbrock. You can close the idle mixture screws completely and it will still burn your eyes. What kind of spark plugs are you using? What is the plug gap?

[mooseboy84]

Well an update...

After several weeks of rainy weekends and finally getting the wheel bearings and pinion seal installed, I bought a fuel pressure regulator and got it setup. The manual say 5.5 psi and that's just about where I set it. I haven't driven yet, but just idling I can tell the fumes are much less and the exhaust even smelled better. I don't know what the psi was before and I didn't feel like cleaning up any extra fuel so I didn't hook up guage first to check. I must have been dumping a lot of fuel down the engine because I would say it smells half as much already. When I had fired the truck up back a few weeks ago and was adjusting the Carb the smell of gas and exhaust just reeked and was starting to make me sick from carbon monoxide. 30 minutes of adjusting Carb and I was really wanting some cats on it.

So thanks for the advice it really was huge help. I still may modify exhaust in future with cats but this was a huge step forward.