I had planned on long tubes, Basani Y and single 3 inch exhaust, is 2.5 better? I can definitely do the 1.7's, any recommendations? Not sure if a bore is required yet but if so we will shoot for 9.5:1 compression target. Not sure about the heads, been looking for GT40's but I can only find the P's and I know headers suck for them. I am fine going this route as long as it will help with the torque issue. I can always round up the MAF parts and do that later when I run out of other things to do.

 

With lowend torque as the goal the idea is to maintain good exhaust air velocity which makes the most of what longtube headers are designed for... increasing cylinder scavenging, that is when the exhaust pulse from one cylinder helps pull the exhaust out of the next one in the pattern. The stock exhaust does have a 3" center section but there are sections in the Y pipe and cat back that are much smaller so the effective max flow volume is really low. With longtubes you're going to ditch all that and start over so pretty much anything you can put together with aftermarket parts will flow a lot better than the stock setup even with 2.5" pipe all the way through. With 3" pipe some or all of the gains longtubes should produce will be lost, really this size pipe should only be used on a max HP build.
Scoirpion rockers get good reviews, and Crane are also good.

 

I run a bassani Y (hooks to the JBAs perfect) 2.5 to 3" with a magna flow 3 chamber & 3" MF hi-flo cat. Runs out to ss mandrel bent over the axle MF "stock" late model ford diesel tailpipe.

Friends tell me it's great but it's a little "log-truckish" to me sometimes.

I'm sure it gives up a bit here & there, but is sure is sweet to work on when necessary.

 

I like the way this guy thinks! It's likely overkill for your goals though as long as you run a SD friendly cam. I agree with the others that said to just keep it SD and build a combo that will work with that. Much cheaper and easier than the MAF swap.

 

So, the bassani y pipe is designed to mate to stock located exhaust so you will not be able to use it with long tubes, but it should work with any shorty header meant to work with the stock y pipe. Long tubes are often recommended on the forum for torque but will require you to fabricate or have fabricated at least the forward portion of the exhaust. The advantage of long tubes over shorties in the 0 to 4000 rpm range is probably negligible, but if any one can show some dyno data to the contrary I would love to see it. In any case replacing the stock catalytic converter with a high flow version is recommended as this the next bottle neck in the stock set up after the manifolds. Most shorty headers make spark plug replacement more difficult, and depending on the design they can be difficult to install/remove in the vehicle.

I think a set of pedestal mount 1.7 roller rockers is a no brainer. I used the Crane Cam Engergizers, which were used as factory parts by Ford for a time.

GT40 heads would be nice a upgrade over the stock E7's, but not really necessary. You can buy rebuilt units from Summit, under the Vege brand part number 2FX1. I would have them checked out by a machine shop before installing. They pop up second hand but they are not as plentiful as the P's as you have seen.

Leave the stock truck roller cam alone. It is a good torque cam.

You can install a better intake manifold, like a GT40 style intake from a Lightning or the Edelbrock 3881 but the price vs. improvement makes them hard to swallow. I have a 3881 installed on my truck and have been very pleased.

If you did everything above you will be pushing the limits of the fuel injectors and possibly the stock trucks computer ability to adapt. I think you could skip the heads and have a pretty sweet set up, or skip the heads and intake and still have a good improvement over stock. Just having a fresh engine will probably be big improvement for you.

Looking forward to seeing another build.

 

And the myth persists, I have seen dyno tests that clearly show this but I can't put my finger on it at the moment, Longtubes generate more output at both low and high rpms while shorties produce most gains at midrange rpms, on the exact same motor shorties do beat longtubes in the 3-4000rpm range. The thing is, these truck engines only have a 0-3500/4000rpm powerband so they won't ever utilize one of the 2 areas where longtubes perform best up at 5-6000rpm, but that just happens to be right where shorties work best. And I think almost without exception everybody that installs a full exhaust system on these trucks goes too big(I did), these motors just don't move that much air and bigger exhaust volume does hurt the bottom of the powerband where these engines spend most of tier time. But I have done several system on both the 5.0 and 5.8 and the very best working examples were the smallest.. not the biggest.

Equal length shorties are the worst for this but standard shorties are no worse than longtubes in most cases. My experience overall with headers and plug access is positive, you might need a wire set with angled boots but that is it.

 

"GT40 heads would be nice a upgrade over the stock E7's, but not really necessary. You can buy rebuilt units from Summit, under the Vege brand part number 2FX1. I would have them checked out by a machine shop before installing. They pop up second hand but they are not as plentiful as the P's as you have seen."

I found these heads on Ebay at of all places, Autozone. They are selling for $202 each and no core charges or returns.

"If you did everything above you will be pushing the limits of the fuel injectors and possibly the stock trucks computer ability to adapt. I think you could skip the heads and have a pretty sweet set up, or skip the heads and intake and still have a good improvement over stock. Just having a fresh engine will probably be big improvement for you."

I plan to keep my factory intake so will the GT40 heads and 1.7 rockers be ok for the Speed Density? I am going to run the long tube headers and single exhaust as well and all smog has been deleted before I got the Bronco. Everything else will be stock.

Thanks

 

I think you should be okay using the stock SD computer, assuming you stick with the factory roller cam.

On the subject of smog equipment - You want the EGR system intact and functioning. If you delete the catalytic converter or replace it with a modern one that does not need air injection deleting the factory air injection system is easy and there is no functional reason to retain it.

 

Yes I would use the stock cam and the EGR is still there but the smog pump and converters were already gone. Where is a good place to get a stock cam or will i be able to reuse mine with 161k miles?

 

yes, it will

 

If the engine was running pretty well, the cam is likely to be okay to reuse, but there are so many factors involved no one can say until you remove and inspect it. You or your machinist should inspect cam lobes and bearing surfaces carefully. Minor imperfections can be polished out but anything major will probably warrant replacement. If you need a replacement I know Sealed Power and Melling make an equivalent but I couldn't comment on the quality.

If it turns out you need or want a new cam Conanski is the one to get advice from. There may be a good off the shelf cam that would be a small upgrade.

 

Okay, I got a chance to take my cam to the machine shop today and he said that everything looked good except for 1 bearing journal. He is going to try to polish it out but just incase he can't, what would be a good replacement Mr. Conanski? I'm fine with stock specs but not sure which one to buy.

Thanks

 

Whoah. If I'm reading this right, the engine computer is $800 but if you have an E40D auto tranny then you also need the $1500 tranny computer. $2300 vs MAF... I'd go MAF.

 

No, stand alone programmable EFI without trans control is $800 & $1500 is with trans control, not an additional.

If you go out & price a programmable stand alone EFI of any type & then add a stand alone trans controler it's well above $1500.

Plus there is zero systems that directly plug in this gen truck.

The Stinger is a game changer for OBS EEC-IV trucks.

 

The Comp Cams 35-512-8 is roughly equivalent to the stock cam with 1.7 rockers.