Hello all,

Before I start please don’t get all upset, I have some questions and valid reasons for them. I’m simply seeking a response to help my situation.

I have a 1983 Ford F150 with a 1987 4.9 L Carb’d engine in it, fully rebuilt and basically new. It is not a fuel injected as the modifications to make the 1983 truck To the fuel injection would have cost a bunch to my understanding. I’m not a big time car guy but have been helping my son redo his truck. He’s 16. So it’s a learning process for us both and I get to teach him the importance of old trucks and engines and stuff what I can.

the old exhaust system was terrible, holes in the muffler, exhaust leak in near engine compartment, nasty looking Cat, now the engine we got luckily from the machine shop as the engine in it was actually a 1968 240 from what I’m told so we got a 300 from the machine shop basically at no cost. I wanted to redo the exhaust since engine is out and it can be done. But I’m on a super super tight budget and cannot afford an expensive cat converter. Now prior to use doing all this engine stuff all the emissions was removed from previous owner. I don’t have any in it. In my state they are not required for smogging purposes. But the cat I think is required, but so dang costly. I’ve read they are bad for increasing back pressure on the engine and costing on fuel milage. I guess I’m trying to find out can I go without a cat? Is there negative affects on the engine without it. I’ve read this truck doesn’t have to have it in my state with antique plates. I’m not for or against them or anything but I’d like to know it I must do it or if I can go without it due to my extreme budget costs. Will it hurt the engine without it? Or be no biggie. I know all the benefits as far as reducing emissions I get all that so don’t get mad at me thinking I’m just trying to eliminate it just cuz. I’m simply trying to figure out if I can be without it for engine purposes only, will it hurt the engine? Hope that helps. The rebuild cost way more than anticipated and I cannot afford a 200-500$ cat right now. Any help would be great thanks yall

 

Won't hurt the engine to run it without the cat.

Cat really doesn't cost any power on an engine like that.

But if it's in poor condition anyway, free yourself of a potential failure and exhaust leak.

 

If your state requires it, then you need one, or something that looks like one. My state does not require inspections for antique tags either, but you most likely will eventually get caught running around everyday on antique tags. They are made for limited use. I see Autozone carries a new universal cat for $114.00.

 

If your state doesn't require a catalytic converter then there's no need to run one. Might want to run the carburetor and distributor that were on the engine originally vs. the ones that were used with the catalytic converter.

 

I was going to say that.
Now if you go with normal plates dose it need to go thru safety & smog check each year or just for the first time to get plates?

State may not "require" a cat or any smog but fed gov dose and if the truck or car came with it it "should" still be on & working but as we all know over time things fall off if the state dose not look for them each year.

His being a 83 and said it has a old cat the carb & dist. are set up for it no way around it.
Now if the 83 was a feed back system then I would replace the carb & dist. for non-feed back parts.

BTW my 81 should have a cat, air pump, ect. and they all fell off at some point and I put 28K on it in the last 4+ years with out issues.

You did not say if you are running the stock log EXH manifold and EFI manifolds for a little more power as they flow a little better than the log.
I run the EFI manifolds with a replacement Y pipe. Y pipe came with the cat but I did not use it.
When my muffler went bad, inlet pipe pulled out, I went with a 94 F150 system for a 300 motor as the pipes are a little larger than the 81 pipes.
I also went with a Thrush welded muffler that is an up grade to the 94 system.
I got 2 middle pipes because I removed the cat and the 94 tail pipe.

If you can swing it get the 94 middle pipes, muffler and tail pipe as they are a little larger. It is a bolt in using hangers for your year.
You will need to cut the metal wire hanger from the tail pipe but that is no big deal.
If running the log manifold get the head pipe for it and adapter to hook the smaller head pipe to the larger middle pipe as they should be different sizes.

I like the rumble of the Thrush welded muffler but I dont know if you would get the same sound, no not loud it is deep, as you have the log and I have EFI that are like shorty headers.
Other reason I also went with the 94 besides larger I can hit any parts store and order the full system for replacement.
Dave ----

 

is it carb complaint though? I’ve looked and found some but not carb complaint whatever that means.

 

Hey all,

Ya I’m in Virginia, new distributor and motorcraft carb. Log intake with EFI exhaust thanks for all the help, I have a Weber y pipe so far trying to go to be rest of the way just making sure I’m good, safety inspection every year without antique plates, so I have no smog and considering no cat but I dunno just want the engine to last a long time so trying to make sure it’s done right, here is the engine and getting her back tomorrow.

 

The guys at the machine shop may have the right answer for your cat question.

 

On the cat I am guessing that the ones for carb may be a little bigger to do its job as a carb would run richer than EFI
Again just a guess.

Do you know if the Weber Y pipe is the same as a factory replacement for a EFI truck?
I would say yes and look up a EXH system for a 1994 F150 less cat if they dont look for it on the safety check.
Like I posted above you can go with a performance muffler like the Thrush welded or go stock.

I cant remember who I got the mid pipe, Thrush muffler and tail pipe from
When checking on line and do exh pipe it comes up with the Y pipe with cat.
I am sure I got them as a kit but cant find from who?

Was back December of 2021 no wonder I can't remember.
Dave ----

 

Carb means California Air and Resources Board. They are the ones that start all this mess. I am not against clean air, but they get a little carried away sometimes. So a CARB compliant convertor means you can install it on a vehicle used in California. Everything else is Federal or all states except California. But wait for it; The crazy democrats that ran the house and senate and when they had a democratic governor in Va, passed a law that by 2030 or 2035 (can't remember the year) Va will start following all the CARB mandates and smog rules that California has. Isn't that great? That also means no more new gas lawnmowers and weedeaters sold, and a certain amount of the new cars will have to be fully electric.

I looked up a 1986 Ford pickup with a 4.9 engine on Autozone, and they have a FEDERAL cat convertor, universal clamp on type for $132.00. That is good enough for where I get an inspection every year. That is the one thing they look for around here, if you have a cat. Some places will also lift the hood and look for a air pump. They do not get into much else.

P.S. I have heard when you get up around DC in Va, they do have sniffer tests. And or they hook a scanner up and check for codes.

 

Ya I ain’t no where near DC and left Cali a long time ago for its dumb laws. Hoping it stays country where I am, thanks y’all. The Weber pipe I got is for EFI stock headers so I’m hoping it fits its out in the garage still in bubble wrap, getting engine tomorrow so hoping to atleast line it up to ensure fitting. I’m not against clean air either but some of this is over the top for sure, I can deal with 132$ or so, just see these on here for like 400$ and am like heck no, so the carb complaint doesn’t mean Carburetor? That’s good to know so basically any cat will work the , I assume. It’s a 4.9 no different than any other 4.9 to my understanding but I’m not super smart with cars, maybe it does need to be a 87 car converter since it’s an 87 4.9 I dunno

 

Cat or no cat will not affect how the motor runs at all. The carb and ignition system have no clue if its there or not. Even EFI doesn’t care if the cats are there or not. All that happens is a light turns on if there are after cat O2 sensors. If its not required by state inspections, no need to stick one back on it especially if there is not a catalyst sticker under the hood. That vehicle is 40 years old, highly unlikely you’re going to get nailed by the EPA.

 

That's a beautiful beast you have right there. My favorite engine out of all in the world. Just wish I could shoehorn one into my Ranger! On the 🐈, while they are not much of a restriction while new, after many miles, and imperfect fuel delivery, they can become clogged. No worries if you don't have one tho.

 

Does anyone know a decent cat for cheap on Amazon that will work for a 4.9 300 on a 1987 f150? Anyone have a link?

 

Autozone has them cheap enough. $132.99 for a universal clamp on converter. AP universal 602205. I see Amazon sells the same thing for $75.00 Just make sure your pipe is 2 inch OD.