Truck is stock except for a 3" single exhaust and a K&N FIPK. I want some more power for towing so here is what I'm thinking of doing. Thorley or Banks headers, stock cat, 3 1/2" single exhaust with a fairly quiet muffler.

Cam, this one

COMP Cams 35-255-5 - COMP Cams Computer-Controlled Camshafts - summitracing.com

or this one

Lunati 61600 - Lunati Voodoo Camshafts - summitracing.com

deciding factor will be the cam that will work the best with my stock SD EFI. I'll use whatever lifters, valve springs and timing chain set the cam manuf recommends.

Thinking of porting the exhaust ports, and slight milling of the heads for a bit more compression. And a HV oil pump with a HD shaft.

Goal is more power at 1800-4500 rpm with near stock driveability and reliability. Hope to run the EFI with no mods, but if some tuning is needed it's not a deal killer.

What do you guys think?

 

Oh yeah, motor is a Ford Factory ReMan with about 8,000 miles on it. Runs good, just feels like a small block pulling the Crewcab 4x4 around. Looking for that big block torque..

 

I like the second cam because of the additional lift. I had a cam custom ground that basically combined you two choices. Less duration but more lift to let the motor breath at higher rpm. IIRC, was advertised 248° duration and .515" lift. It improved gas mileage and pulled better over the mountains.

 

Did you use that cam with SD EFI or MAF? Custom could be the best way to go, cause both cams I posted have a compromise. The Lunati has 112* lobe centers, I've heard 114* is what my SD EFI wants. The Comp Cam has a bit more duration and a bit less lift than I'd like. I think I'd like the Lunati, just with the wider LSA.

Thanks for the info.

 

Here's another cam that could work

Crane Cams 353904 - Crane Truck Power Cam and Lifter Kits - summitracing.com

very similar to the Lunati posted earlier. Does anyone have any advice on what brand of cam to use or not use? I want this thing to last a long time..

 

Yeah, I like that one better too. Look at all the valve lift on the exhaust, where the 460 needs it.

 

Just make sure you get towing instead of racing if you go for headers. If you go for racing headers your low-end torque will suffer. The headers designed for motorhomes will give you maximum low-end torque and this is where you need it for towing.

 

I've pretty much decided on Banks or Thorley headers. Whichever I can get for the best price. Both of them are Tri-Y designs, idle to 5000rpm.

The more I look at the cam specs the more I'm liking the Crane. It has the shortest duration of all of them so it should be the most EFI friendly... If not I'll be posting about re-installing another stock cam...

 

If your keeping the stock cat, you won't need a "fairly quiet muffler". The exhaust will have a nice mellow tone with the stock cat and it will not be loud. I had this setup for several years (stock cat and 3.5" single all the way back with no muffler). People could not believe it wasn't louder with no muffler. If you yank the cat though, LOOK OUT, because it is going to get loud.

I now run a straight (no cat or muffler) 3.5" and it is very loud, maybe a tad too loud.

 

Good info, if the Cat muffles that much I would have bought too much muffler without your input. I want mine to be pretty quiet, so maybe a Flowmaster 40 series and the Cat will end up about where I want it.

What would you compare the Cat only system to, sound wise? Was it as loud as a Flowmaster without a Cat?

 

Cats are great mufflers and exhaust restrictors. I am thinking of removing both mufflers from my Crown Vic PI, to make it sound better. The only part that makes me hesitate is that the entire exhaust system is stainless steel.
Alas my 460 is sans a cat as it is a 1984 F-250 Heavy Duty, aka light 1 ton and has no cat, hence a muffler with a 3" hole down the middle.

 

I dunno, I would say something similar to a late model factory stock GM fullsize pickup or Nissan Titan V8, only a little louder and deeper.

No.
Not nearly as loud as a Flow with no cat would be.

I really think if you want any sound at all AND you plan to keep your stock cat., you will love a straight 3.5" after the cat. Not too mention save a few bucks by not having to buy a muffler.

I have heard lots of newer vehicles with Cat only exhaust and it is usually pretty loud, I suppose the newer Cat's are more efficient and/or less restrictive? On ours though, I could not believe how much it muffled.

My philosophy is: You can always add a muffler later if its too loud.

If you decide to buy a muffler, I would consider a straight through design for minimum restriction (i.e. not a Flowmaster). It might also be worth the extra dough for Stainless if you plan to keep the truck long, the ol'460 creates alot of heat. One of our forum sponsors has what appears to be a very high quality alternative to the popular straight through designed mufflers and it is a little cheaper. Item Details

Sorry for the book, let us know what you go with and how it turns out.

Eric

 

Oh, one more thing.

I asked the muffler shop who welded my 3.5" onto the Cat. for me to cut a 3.5" hole into the housing of the Cat. to eliminate the 2.5" bottle neck. They refused. But if your muffler shop would be willing to do that, I feel that it would at least help a little in the effort to create more flow and horsepower. Not sure how much it would change the sound, I don't think much.

 

Thank the Feds for their refusal. The $10K fine for modifing or removing a cat just isn't worth it to them.

 

Naaa, I doubt these guys were too worried about modifying the Cat. case., especially since they seemed plenty willing to just wack it off for me. Their stated reason was, "we don't think we can do it with out damaging the case too much and causing it to be weak?" Sounds like a pretty "weak" reason to me?

I think more than anything, the soldador wanted to get the Gringo's money and send him on his way with as little work as possible.