Well I thank you for your help. I'm an old carb guy. I don't know much about EFI.

In the process of headers etc. I'll be removing the air injection system as well.

 

double post

 

I understand that long tubes will help with torque. So should I get these instead and have my exhaust shop fab the rest?

https://www.summitracing.com/parts/b...rd/model/f-150

 

unless i am building something for all out power, I will never again take long tube headers over shorties. they are just so much easier to deal with.

i have right at 4000 miles since swapping an explorer engine into my 88. it has the gt40p heads, the stock explorer cam, the stock 88 intake, ev6 injectors, smaller crank pulley, and shorty headers going into a single 3".

the power difference is night and day, my 6000 pound supercab 4x4 can nearly keep up with my 2003 turbo'd jetta, and it has averaged 15mpg, with half that mileage pulling various trailers. it is still running the factory computer, although i would like to change it to mass air.

it has 3.55's on stock tire size (and it has the m5r2 5 speed) and it still really needs the 4.10s, it only goes into fifth if there isn't any hills and i'm doing 70+. even though it has all the extra power, it is still a 302 and doesn't like being below 2000, and seems to do best between 2500 and 3000rpm.

 

Ok so finally getting around to this. Long story. I had to rebuild a triumph speed triple, then the motor on my sons jetta. Then renovate the house. etc etc.

I have the headers and y pipe listed above. What do you recommend for muffler? I want a single inlet with a double outlet. I will dump them both out in front of the passenger rear tire. I don't want loud flowmasters but something that is throaty without being annoying. Currently this is my DD as my 200k mile Subaru just blow the motor. You know what they say, if it weren't for bad luck I wouldn't have any.

 

Dyno max super turbo.

 

The diameter will make about as much difference as your muffler choice when you are discussing aftermarket exhaust. A pair of 2" x 36" perforated glasspacks is a really nice sound (aside from the possible drone caveat) whereas a pair of 3" x 18" would be absolutely obnoxious. The same will apply to any other muffler designed for a bigger flowing engine.

Thank you for not using a Flowmaster, regardless of what you go with. They sound horrible on everything!

 

Well it will be a single 2.5" as that is what the exhaust is.

On a second question. This ypipe and cat were obviously designed to work with the smog pump that I am removing. Should I just weld this line closed?

 

If you're not using the pump, then yea, plug it.

 

If you disable the AIR injection, the last 2 stages of your 3 stage cat will not work properly. Don't know if that's important to you.

The_hetz wrote: "Thank you for not using a Flowmaster, regardless of what you go with. They sound horrible on everything!"

And what's wrong with Flowmaster? They sound fine on my car:

 

I don't care. I assume it won't have negative effects to performance?

 

That's one thing he and I agree on.

 

Not sure, but if the exhaust residues are not properly combusted in the cat, they might clog the last 2 stages of the cat. You would be better off without the cat.

 

Or better off with a single stage high flow cat if he has to have one

 

I certainly want to have one. This is part of the reason I started this thread. In order to not buy something, or buy something wrong. Damnit apparently have a cat I don't need. So on inspection I won't get dinged for lack of an air pump. However I will get dinged for lack of a cat. In my past life I just would have gutted the cat an call it good. But now as I'm older I would prefer to keep it as clean as possible within reason.

https://www.summitracing.com/parts/s...3500/overview/

This looks like it will work.

Or what about this one?

https://www.summitracing.com/parts/f...0125/overview/