Grand Willys Project

[Blue Fin]

That sir is art!

Really moving along well.

[SeaComms]

Damn they look sweet. Will the rest of the exhaust need a sharp bend to clear the rear gearbox cross member or is that an optical illusion?

[Tassie Jeeper]

Originally Posted by SeaComms

Damn they look sweet. Will the rest of the exhaust need a sharp bend to clear the rear gearbox cross member or is that an optical illusion?

i could be wrong but the cross member looks to have about 1-2" of clearance

[Gojeep]

Thanks for the comments guys.

The exhaust will take a 90* bend to go under the trans just in front of the cross member.

[Gojeep]

Thanks for the comments guys.

The exhaust will take a 90* bend to go under the trans just in front of the cross member.

[Gojeep]

On the right front cylinder head at number 2, there is the EGR port on the 5.7 which is not on the 6.1. It comes out just if front of the exhaust port in the head and then enters the manifold where it makes a sharp 90* turn into the exhaust runner.


Some people just use the 6.1 gasket and leave it blocked off, but you will get a code showing low EGR flow. Also it runs a little cooler they say with it running so I will make sure it is. I placed the stock gasket over the flange so I could mark out where the extra flange bolts needs to be drilled as well as the position of the EGR port.


The extra flange hole needs to be drilled 11 mm like the others in the flange apart from the slotted one shown. A slot needs to be made from the bigger circle so the EGR can flow into the exhaust primary.


The flange is 3/8" thick so used a die grinder to make a slot just over 3/16" deep


I also cut the gasket to give more area for the gas to flow into the primary as it would no longer act to help seal anyway with the gas running on one side of it and would burn some of it away over time.


A good thing about these headers is that all the lower bolt holes are slotted so I just screwed in the bolts part of the way through the gasket. This helps keep it in place and the header was slipped over the bolts and the rest of the bolts screwed in with my fingers. Having a stand to support the other end of the headers makes it easier too when doing it by yourself.


Can see how the EGR port sits in the head. Very tempted to die grind a slot on this side too, but others have reported it works fine without doing that when using the 6.1 stock manifolds on these. Be very easy to just drill through the port into the EGR port, but don't know where the oil and coolant passageways are and hate to drill through one!


The extra forward hole can be seen here that the 6.1 doesn't have. So remember to take that into account when buying your replacement M8x30x1.25 bolts. You will need a total of 17.


I was happy to see that these headers cleared the bell-housing just fine. When you run the 6.1 stock manifolds on these, the bolt hole protrusion shown here needs to be cut off.


Another side done.

[Gojeep]

Here is a problem you will face on the 5.7 but not the 6.1 as well. The dipstick tube is supported by the first bolt in the header but can't be bolted back due to the difference between the manifold and the flange thickness.


You could run a 6.1 dip stick, which would have a longer support bracket, or make up a spacer like I have done. I decided to use the original manifold bolt and cut a spacer from this solid bar I had.


Bored out the spacer after cutting it to length and used the nut that held the old heat shield on to keep the dipstick tube in place instead.
Also just could have used a longer flanged bolt like the other new ones too.


Bolted on the mid pipes that came with the headers. These now end with factory flanges and in the same position where the stock 6.1 SRT8 cat back system bolt on or after market ones.


These even cleared everything! Seems a shame to cut them up to fit real cats in place! I ordered without cats, $200 cheaper, and they just have these fake ones instead. You can order with their slimline cats but they will throw a code just like nearly every other aftermarket cat on the later models. Only factory cats won't and some sold now by Kooks. So I will have to find someone with good tig skills to weld some in for me as not worth setting up my mig for this little job.


Was able to run all the O2 sensors in place as well after cutting a couple of ties that were holding the plugs to the loom. The furthest one I might buy an extension for. Make sure you label the plugs on the loom side as very easy to plug a after cat sensor in a forward cat one and get a bunch of codes as a result!


The cross over now happens to the rear of the transmission pan instead of in front of it. I'm not so keen on the cat placement under the pan, so when I fit the factory one, will add it further along on the other side.


Got the original front driveshaft lengthened the amount I moved the engine cradle forward, so now can see if it clears everything. Plenty of clearance over the cross over pipe.


Misses the header too so all good to go. Who would have though all this would bolt up to a 5.7, even though for a 6.1, and in a 1948 Willys Truck frame!